coExtra Flashcards
High level
Less efficient
White box
Knows source code
What do viruses do
Damage or delete data
Regulations online to
Keep kids safw
What is the link layer?
This is where the network hardware is located. This layer attaches the MAC addresses of the sender and recipient so the packet can be directed to a specific device on a network.
What are some of the positives of networks?
User profiles and security can all be managed centrally.
All files can be backed up centrally.
Software can be distributed without it having to be installed every time.
Printers can be shares.
internet connection can be shares and files can be stored on a file server so they can be accessed.
What are some of the negatives of a network?
ardware can be expensive
If file server goes down, nobody can access their files
Could lead to loss of data
Viruses can spread easier
Hard to manage
What are some advantages of bus network?
Cheap to set up
Easy to set up
Good for smaller or short term
No reliance on central node
What are the negatives of star network?
Expensive to install
Extra hardware is required
Harder to set up
Name some positives or star topology?
Faster transmission of data
Less likely to experience errors/data traffic problems
A faulty connections disables one computer unless it is the hub or switch
What is cyber security?
Protecting networks, computers, data and programs from attack damage or unauthorized access and is done through processes practices and technologies.
Phising
Impersonating
What are the positives of databases?
Makes processing more efficient, reduces storage requirements.
Characteristics of flat file databases.
Very inefficient, difficult to query and used for small/trivial data sets. Data is often duplicated, also suffers inconsistencies between records. This can compromise the integrity of the data.
What is the difference between using a GUI and CLI?
Command line interface is much quicker.
What is the difference between system and application software?
System is run by system in background for example OS or encryption whereas application is run by user to complete a task.
BIOS
Controlling hardware at start up sequence
What are the two main types of system software?
Operating systems and utility software.(just software is like basic applications like games or browsers which is in the other ring).
How does the operating system do things
User authentication, makes sure users must prove who they are, protect against malware, blocks access to specific vulnerable areas of the pc.
What does WAN have to use
Encryption
Draw the two round dots symbolising the terminators at the end of each side of the BUS.
okay.
Why does everything stop working if the bus goes down?
The cable splits so there are two open ends with no terminators so the data is not absorbed at the end which causes it to reflect and cause problems. Star only impact one node/device UNLESS it is central hub or switch or server as they are connected individually.
PAN
not always wireless but does not need extra hardware unless it is wired as WAP is always required anyway.
What are the advantages of hydrogen fuel cells?
They will produce electricity for as long as you provide hydrogen. They do not get less efficient the more they run and they can be a source of drinkable water for example on a space craft.
What are the disadvantages or rechargeable batteries?
They run out and need to be recharged, they can also store less energy the more charging cycles they go through and eventually need to be replaced.
What are the disadvantages of hydrogen fuel cells?
Run on hydrogen which is explosive and difficult to store safely they produce a relatively low potential difference or voltage so several are needed together.
What are the advantages of rechargeable batteries?
They can produce a large potential difference.
What is another positive of closed source for the user?
Often will have more online help and support as they realised their code is unavailable.
pipette.
Small volume of solution in bottom to make it accurate.
What are anti bumping granules for?
To make the liquid boil more smoothly-small bubbles of vapour form on the corners of the granules and reduce the risk of the liquid boiling over.
What is bandwith?
The maximum rate of data transfer across a given path. The more people online, the more bandwidth is used up.
Make sure electrodes dont touch.
This would create a dangerous short circuit.
What do you always need to say?
Without consent.
What is an example of lossless compression?
.gif
What is an example of lossy compression?
.jpg and .mp3
What is not compression.
.bmp
What is RLE stored as?
Frequency/data pairs
What is system software?
Programs that are needed to enable the computer to function, including the OS, utilities and programming language translators and library routines.
What does the OS manage?
Processors, memory, input/output, applications, security.
How does the OS manage processors?
anages the use of the processors resources, task manager, the OS provides a tiny slice of processor time.
How does the OS manage memory?
OS manages where in memory each program and the data it needs will go.
How does the OS manage input/output devices?
The input is processed and the computer will generate outputs. The OS takes over and controls the sending of data. Each I AND O has a device driver.
How does the OS manage applications?
The OS interacts with applications through an Applications program interface(API) which allows the application to communicate with the operating system. Once an application is installed, it will need t communicate with the operating system to execute modules.
How does the OS manage security?
Controls access to ta computer by setting up passwords for different users, this blocks access to files and software without password. Sets up access rights and privileges for different users. Encrypts files stored on the hard disk and automatically downloads updates to ensure security loopholes are patched.
What do embedded systems use?
No OS and a microprocessor.
What are some strange things about embedded systems?
System held in non-volatile memory and some firmware devices are permanently installed and cannot be changed after manufacture. It is not possible to update hardware or attach peripherals.
What is good about embedded systems?
More reliable, optimised and efficient. And use less resource
Star topology positive?
Consistent performance even when the network is heavily used.
IMAP.
Stores email messages on a server and allows users to view and manipulate the messages.
SMTP?
Sending email messages between servers, used for relaying or forwarding messages form one mail server to another if there are different email service providers.
What is firmware?
Permanent software in read only memory.