MIDTERM Flashcards
1
Q
Internet
A
network of connected computers that the web works on
2
Q
world wide web
A
the pages you see when you’re at a device and you’re online
3
Q
client-server architecture
A
a computing model in which the server hosts, delivers and manages most of the resources and services to be consumed by the client (data tier, logical tier, presentation tier)
4
Q
1969
A
the year the internet was created
5
Q
1990
A
the year the world wide web was created (URL, HTTP, HTML, JS)
6
Q
1993
A
the year web GIS was created
7
Q
2009
A
the year ArcGIS was created
8
Q
Web GIS
A
a Geographic Information System distributed across the internet to communicate geographic information visually on the world wide web
9
Q
two-tier architecture
A
direct link between client and data source
10
Q
data tier
A
database / data storage
11
Q
logical tier
A
processes data and consists of GIS server (provides GIS services) and web server (provides web services)
12
Q
presentation tier
A
the user interface
13
Q
Web 1.0
A
refers to tools for publishing static information that is “owned” and considered proprietary, fact checked and attributed. Those who had information are sharing it with those who want it. INFORMATION SHARING
14
Q
Web 2.0
A
web pages that visitors can add to or change (e.g., Amazon reviews) - Distributed Collaborative. INTERACTIVE
15
Q
Software as a service (SaaS)
A
a software distribution model in which a cloud provider hosts applications and makes them available to end users over the internet (ArcGIS Online portal)
16
Q
Infrastructure as a service (IaaS)
A
e.g., Amazon EC2 – when the hardware infrastructure—the physical servers and networking equipment on your premises—is replaced by virtual machines and virtual networking provisioned and configured using the administrative interfaces of the cloud platform of your choice
17
Q
Platform as a service (PaaS)
A
provides an application platform or middleware as a service on which developers can build and deploy custom applications
18
Q
cloud-based deployment
A
using ArcGIS Online as a Software as a Service (SaaS) to manage, publish and share our spatial resources over the web
19
Q
on-premises deployment
A
disconnected from Internet, customer owned GIS Server (ArcGIS Server)
20
Q
hybrid deployment
A
any combination of ArcGIS Online + ArcGIS Enterprise
21
Q
firewall
A
security tool that restricts the number of ports on your machine through which traffic can be sent to and received from other computers
22
Q
reverse proxy
A
a type of proxy server that retrieves resources on behalf of a client from one or more servers. These resources are then returned to the client as if they originated from the proxy server itself
23
Q
five types of content in ArcGIS Online and Portal for ArcGIS
A
data, layers, web maps, tools, and apps
24
Q
workflow for creating web apps
A
data > hosted layer > web map > web app
25
components of a web app
basemaps, operational layers, and tools
26
three principals of WWW technology
HTTP, URL, and HTML
27
HTTP (Hypertext Transfer Protocol)
Defines a set of rules and procedures that Web clients and Web servers use to communicate with each other
28
URL (Uniform Resource Locator)
Specifies where an identified resource is available on the Internet
29
GeoServer and MapServer
examples of web GIS servers
30
Apache / Tomcat
examples of web servers
31
PostGIS/PostgreSQL
examples of databases
32
HTML (Hypertext Markup Language)
The main language for creating Web pages
33
HTTPS (Secure Hypertext Transfer Protocol)
The use of ordinary HTTP over an encrypted Secure Sockets Layer (SSL) connection
34
stateless (e.g., HTTP)
The connection between the browser and the server is lost once the transaction ends
35
Server-side technology
web servers (e.g., Apache Tomcat) and programming languages (e.g., Java, Python) that run inside them
36
Client / browser-side technology
web browser (Implements HTTP, HTML, and JavaScript) and programming languages
37
XML and JSON
two main formats for exchanging data over the Web. XML is tag/markup-based. JSON is more like data format
38
types of Geospatial Web service services
map, data, analytical, and metadata
39
GIS database
the underlying support for Web GIS application
40
Web GIS client
represents the end-user interface
41
Thin client
Client sends request to server, server processes the request, and client's browser displays information. A thin client's job is just to display what is provided by an application server, which performs the bulk of any required data processing. Lot of pressure on server
42
Thick client
A thick client is a type of application where the bulk of processing and operations happen at the client side or on the machine where the application is installed. Less pressure on the server
43
User experience principles
fast, simple, fun
44
types of operational layers
ready to use layers from Living Atlas of the World and feature layers (a hosted feature layer is a layer created from a vector dataset that is stored and served from ArcGIS online). Non-hosted is maybe you're editing a layer in ArcGIS Pro
45
Feature service
web service that supplies geographic features and attributes to clients
46
ArcGIS Arcade
Lightweight and secure expression language designed for customizing labels/popups
47
Web AppBuilder vs Experience Builder
Web AppBuilder has less flexible layouts, less styling controls, can't integrate 2D/3D in one app, and can't perform action triggers. Both have a "What you see is what you get" user experience
48
Website
A collection of web pages put together, a front-end user interface through a web browser, Meant for use by humans, uses HTML, CSS, Java Script, has a URL, runs on a web server
49
Web service
a program that runs on a Web server to support interoperable machine-to-machine interaction over a
network. Unlike a website, doesn’t have a user interface; accessed by HTTP methods
50
Geospatial Web service
a web service that provides access to, or data processing on, geographic information
51
Interoperability
the capability to communicate, execute programs,
or transfer data among various functional units in a manner that requires the user to have little or no knowledge of the characteristics of those units
52
Types of map services
Feature (vector), image, Image map services, Tiled (fixed size image tiles)
53
Caching
the server draws the map at several scales and stores copies of the map images. The server can then distribute these images whenever someone asks for a map.
54
load balancing
distributing network traffic across multiple servers (hardware and software approaches)
55
Geospatial mashup
An integration of multiple data layers or datasets
dynamically, often from multiple sources, into a new application. Geomashup is a mashup where at least one of the contents or functions is georeferenced.
56
Mashup design and implementation
Define objectives, Search for the Web resources you need using geoportals, Publish your contents and functions when they are not available on the Web, Organize the contents and functions into basemaps, operational layers, and tools, Test, enhance, and deploy the application
57
Web 3.0
also known as “the Semantic Web,” provides personalization that allows users to access the Web more intelligently. The goal is to tailor online searching and requests to users’ specific search patterns, preferences, and needs. Artificial Intelligence. IMMERSIVE
58
semantic
MEANING - the power of recognizing, understanding, perceiving, and then accordingly responding.
59
2014
s the year that access to the internet via mobile
| devices exceeded the desktop. THE MOBILE REVOLUTION
60
Mobile GIS
integrates Mobile devices and their OS and Wireless communications for Internet access
61
Types of mobile GIS applications
Location-based services (Google Maps, Yelp, Uber), Volunteered Geographic Information (report accidents, georeferenced Tweets), Virtual Reality (replaces reality - simulation of 3D environment), Augmented Reality (adds to reality - overlay digital information on smartphone, e.g., Pokemon Go)
62
Browser-based mobile app development
apps you create with ArcGIS web app templates, run inside web browsers. Single version of code
across all platforms.
63
native mobile app development
e.g., Collector, Explorer, Survey123. require platform specific programming skills. expensive. better user experience. Offline mode
64
Hybrid-based mobile app development
combines native apps component and browser-based. one code base, multiple platforms
65
ArcGIS Collector
allows adding, removing, and updating geometries (points, lines, and polygons) and attributes. MAP CENTRIC
66
Survey123
Point collection only. FORM CENTRIC
67
Geoportal
Web sites where geospatial information can be
| discovered, accessed and used. – facilitates geospatial information sharing between provider and user
68
Spatial Data Infrastructure
the infrastructure that facilitates the discovery, access, management, distribution, reuse, and preservation of digital geospatial resources. Objective is to maximize the overall use of geographic information in both
public and private sectors
69
Geoportal roles
Publisher (provide content), Administrator (manage content), and User
70
Metadata
who, what, when, where, why and how - usually in XML format
71
Geospatial metadata standards
A common set of terms and definitions that describe geospatial resources - facilitates the location and readability of the metadata by both humans and machines
72
Distributed geoportal catalog
Performs search from multiple catalogs. Geoportals with distributed catalogs need to distribute user’s search requests to the participating catalogs (federal/state government, NGO, universities), merge the results from each catalog, and then present the merged results to the user.
73
Centralized geoportal catalog
All metadata records contained in one catalog.
74
Geoportal challenges
complexity of metadata standards, semantic search (meaning vs spelling), Protecting copyright
75
Digital Rights Management
e.g., copyright statement, license, managed access, watermarking, Encryption
76
Temporal resolution
time interval a t which events are sampled
77
Internet of Things
The network of physical objects/devices or
"things" embedded with sensors and network connectivity, which enable these objects or "things" to collect and exchange data
78
Internet of Things examples
smart heath, smart retail, precision agriculture, smart homes
79
Real-time GIS
Continuous stream of events flowing from a sensor or feed
80
GeoEvent Server
can connect numerous types of streaming data, perform continuous data processing and analysis, and send updates and alerts when specified conditions occur, all in real time -- enables real-time event-based data streams to be integrated as data sources in your enterprise GIS for use in web maps and apps
81
Geofence
a virtual geographic boundary (admin-defined), defined by GPS or RFID (Radio-Frequency Identification) technology, that enables software to trigger a response when a mobile device (user-exposed) enters or leaves a particular area
82
Poll method for real-time data delivery
```
real-time GIS data is first saved in a feature class
and then exposed as a feature or map service for the client to poll periodically (pulls the latest state) refresh interval
```
83
Push method for real-time data delivery
real-time GIS data is pushed out to the client
| immediately as stream services vis a WebSocket.
84
time-enabled layer
Layers that have been time-enabled and have either a single date attribute field or two date fields (beginning & ending data fields). can be point, lines, or polygons.
85
Temporal data
include observations of objects and events that move or change through time
86
National Spatial Data Infrastructure
Promotes collaboration at the local, regional, and national levels the private and non profit sectors, and the academic community. "Democratization of data”
87
Data-duplication-based NSDI 1.0
involves exporting, transporting, and importing the data - slow, high cost, copyright concerns. Government-centric
88
Web-Services-based NSDI 2.0
User Generated Content, VGI, cloud computing. User-centric
89
SOAP (Simple Object Access Protocol) web services
XML-based protocol used for data exchange between applications PROTOCOL-BASED
90
RESTful (Representational State Transfer) web services
based on HTTP, which is a request-response protocol, and uses JSON for a data format, which is super browser compatible ARCHITECTURE-BASED. client/server, stateless, layered, and support caching
91
Uniform Resource Identifier
a character sequence that identifies a logical (abstract) or physical resource -- usually, but not always, connected to the internet. A Uniform Resource Locator (URL), or web address, is the most common form of URI.
92
Raster tile layer
A set of square images placed next to each other, each with fixed geographical area and scale
93
Dynamic map services
Maps generated on the fly at the time they are requested by a user. Dynamic layers allow clients to change layer appearance and behavior on the fly in a map service.
94
Tiled map services/layers
Maps are pre-rendered, Often for static data. Useful for the static and large datasets such as satellite images and street maps.
95
Vector tile layer
store a vector representation of the data. Client-side rendering of vector tiles allows for vector tile layers to be customized
96
Map image layers vs. feature layers
Server-side rendering vs Client-side rendering
| Limited client experience and interactivity vs Rich client experience and interactivity
97
Geoportal roles
Provider, Registry (Geoportal), and User
98
How Web GIS works
1. The client reaches the server through a URL
2. Requests from the clients to the server are sent relying on the HTTP
3. The server then responds to the requests and send them back through HTTP
99
GIS server
A machine that provides GIS web services and does things related to sending and processing geographic information
100
Operational layers
thematic representations of your data - represents both data and visualization (feature services or feature layers)
101
Basemap layers
provide reference or context -- Should be cached (tile services)
102
XML vs JSON
JSON has a smaller file size and efficiently transmits data to the web as compared to XML. JSON accesses data through JSON objects whereas XML needs data to be parsed. JSON is easily readable as it has a more organized structure of code.
103
Best practice for thin vs thick
Current best practice recommends basemaps done by the server and operational layers typically render by the browser, unless the data size is too large for the browser to handle. Essentially, easier functions are performed by the browser and complex functions are handled by the server.
104
What you see is what you get
The idea that with app builders, your design looks like the final product
105
Methods for optimizing web services
Caching, load balancing, require role-based authentication
