K2 (25%) Interaction & Compatability Of Code On Different Platforms

Question 1

What is a stack?

Answer 1

A stack is a solution or software stack, a set of components required to create a complete platform.

Question 2

What is the LAMP stack?

Answer 2

LAMP stack is a web service stack.

Named after the four original open-source components:

• Linux (operating system)
• Apache (web server)
• MySQL (relational database management system)
• PHP (server-side scripting language)

It can be used to build dynamic websites and web applications.

Question 3

What is linux?

Answer 3

Linux is a family of free and open-source operating systems.

Common distributions include Ubuntu, Debian and Fedora

Commonly used as server operating systems.

Operating system is software that manages computer’s hardware and software resources as well as the platform the user used to interact with computer.

In LAMP stack, linux is used as operating system on the web server.

Question 4

What is Apache?

Answer 4

Apache HTTP server is a free and open-source web server.

Currently the most popular web server software in use & often runs on Linux distributions.

Primary function of web server is to store, process and deliver web pages to clients.

Question 5

What is MySQL?

Answer 5

MySQL is an open-source relational database management system

Purpose of the database is to store information eg user info, login details, web page content, images and videos

Question 6

What is PHP?

Answer 6

PHP (Hypertext Preprocessor) is a server-side scripting language designed for web development.

Can also be used as general purpose programming language.

The code is interpreted by web server which results in web page.

It can be embedded into HTML code or used in conjunction with content management systems & web frameworks

Question 7

PDF

Answer 7

PDF = Portable Document Format

A file format used to present documents in a manner independent of software, hardware or operating systems.

Extension is .pdf

Many applications have ability to create pdf’s including most operating systems. Pdf viewer are generally provided free of charge. Most common is adobe acrobat.

Question 8

HTML file format

Answer 8

HTML = Hypertext markup language

A file format used to present web pages

Extension is .html or .htm

The docs can be opened using text editors and then viewed or edited. But must be opened using a web browser to be viewed as a webpage

Question 9

Image file formats

Answer 9

There are numerous file formats used to present images

Most common:

• GIF (Graphic Interchange Format)
• JPEG / JPG
• PNG ( Portable Network Graphics)

Question 10

GIFs

Answer 10

GIF images are compressed using lossless data compression (no loss of quality) and supports small animations but have palette limitations

Thus are suited to images with simple graphics or logos with solid areas of colour rather than gradients

Extension .gif

Question 11

JPEG / JPG

Answer 11

Joint Photographic Experts Group

JPEG images are compressed using lossy data compression ( quality is affected)

File type is well suited to realistic images eg photos but less suited to line drawings and textual or iconic graphics.

Most commonly used image file type for web pages where it is important to reduce amount of data on a page

Question 12

PNG file type

Answer 12

Portable Network Graphic

PNG images are compressed using lossless data compression (no loss of quality)

The PnG file type was developed for transferring high quality images on the internet and is most widely used lossless image compression format online.

Question 13

Video / Mpeg

Answer 13

Mpeg = moving Picture Expert Group

File format used for compressed audio and video for digital storage

Files are usually compressed using MPEG-1 or MPEG-2
Popular for online distribution as can be streamed or downloaded quicker than other video formats

Extension is .mpg , .mpeg or .mpe
BUT as MPEG also refers to form of compression it can also have file format that reflects the compression codec eg .mp2 or .mp4 (Others can include .xvid, .mv4 etc)

In order to play MPEG, you need to use player with corresponding codec for the files compression method.

Most common video players will have code a for MPEGs already installed

Question 14

Audio / MP3

Answer 14

Audio coding format for digital audio

Originally derived rom the mpeg standard audio format but later extended

MP3 files use lossy compression meaning some quality loss but vastly reduced file sizes.

Small file size makes the perfect for online sharing and in 90s peer to peer file sharing software combined with ease of transferring mp3 files resulted in widespread copyright infringement.

Question 15

Development cycle - what are the stages?

Answer 15

Analysis
Design
Development
Testing
Evaluation

Question 16

What is the analysis stage of development cycle?

Answer 16

Analysis involves breaking down the problem into smaller more manageable chunks and identifying key components eg data being used, procedures required, future potential, current issues that new solution must address

Question 17

What is design phase of development cycle?

Answer 17

Design consideration depend on project type BUT common concepts to consider include structure for solution and common algorithms required, how data will be accessed, inputs, outputs required by the system, a user interface, security and hardware required

Question 18

What is development phase of dev cycle?

Answer 18

Once problem is broke down in series of well defined tasks, programming can begin.

During this stage, developers refer to analysis and design stages to ensure solution fits requirements of user. Sometimes it may be necessary to change the way the solution is implemented. Perhaps the original plan does not work correctly or more efficient solution is established.

Question 19

What is testing stage of dev cycle?

Answer 19

Testing is how we ensure code does what it is supposed to do.

Each module of code is tested to ensure it preforms correctly, is secure and cannot be broke . Any issues identified must be fixed before moving on.

Question 20

What is evaluation phase of dev cycle?

Answer 20

Once solution has been built, it must be evaluated. Does it do what it is supposed to do? It can take a few months of use to check. Any further dev or changes or issues can be fed back to developers and addressed.

Question 21

Widget

Answer 21

Easy to use software applications or components made for one or more software platforms.

Often developed for social media platforms with the service hosted bu the social network but accessible to all users.

This means users can use widget applications to easily integrate social media feed, photo albums or profile info into their own web pages

Question 22

API

Answer 22

API = Application Programming Interface

A set of rules for the they way two software components communicate with each other.

Many organisations use APIs to allow their data to be accessed by other developers or clients. This allows organisation to control and secure what access they allow.

Question 23

XAMPP stack

Answer 23

X = cross platform
A= Apache / apache http server
M = MariaDB (formerly MySQL)
P = PHP
P = PERL