Extra Flashcards
Why was Unicode created?
To be able to represent additional/more languages and symbols not available in the ASCII character set. To represent characters from other character sets and ones that are not English.
How is data read from optical disks?
Disk rotates at high speeds and the laser head moves across the radius of the disk and the laser shines onto the disk. Tiny indentations/pits/bumps reflect light differently to lands/flats. Different colour of dye reflects or blocks laser light. Reflected light is interpreted into 1s and 0 representing data stored on disk. Data is stored on a signal spiral track rather than concentric tracks.
Why would a company not want to make their source code of the software available?
So third parties cannot insert/modify code and pass it off as original as it affects profitability. Algorithms cannot be copyrighted and therefore need to be protected to preserve commercial advantages. Hacking/cyber security as hackers could identify vulnerabilities in the source code and use them to create targeted attacks. Copyright of code-they may not want others to have access to what they have developed.
What are some advantages of star topology compared to bus?
Less likely to experience transmission errors/data traffic problems(contention issues). Faster transmission data. Fewer/no collisions if a switch is used rather than a hub. Also better security potentially as data is not broadcasted to all machines if a switch is used.
What are some negatives of star topology as oppose to bus?
It is harder to install and requires more cable. It is more expensive to install as more cable and hardware is needed. Switch/hub/central device may fail breaking the entire network.
What are the positives of a network?
Sharing of resources such as printers and storage space. Managed/central backing up of data. Central installation and management of software by network admin. Monitoring of users and network activity centrally by network admin. Hot Desking/users can log onto any machine. Ability to use communication tools between computers and centrally managed access rights. Rapid data sharing and it allows decentralised/home working.
What are the negatives of networks?
Spreading of malware and cost of infrastructure. Cost of network admin required to run network and dependency on network hardware.
How do firewalls increase the security of a network?
It monitore network traffic and makes sure only the authorised traffic is allowed. It also opens and closes porte as necessary. Prevents unauthorised access into the network by checking IP/MAC address and the packed content. Prevents unauthorised transmissions from inside the network to external locations (insider attack?).
How can passwords authorise a user?
A set of characters that is known by the person who is being authenticated. A set of characters is entered and compared against a database/recorded version.
How can biometric measures authenticate?
Measures such as fingerprint, facial, iris or voice print that use the users physical features to prove who they are.
Email conformation authentication?
Sends an email which requires a valid email adress and for the recipient to respond to prove the email and hence the user is valid.
What other measures of authentication are there?
Two factor authentication, security questions and authenticator apps.
Does hex use more space?
The number will still be represented using binary in the computers memory so it will take up the same amount of memory space.
What are two advantages of using unicode in comparison to ASCII?
Can represent a wider range of characters and characters from a wider range of languages. Can represent characters used in scientific/mathematical specialist documents.
How many bits is ACII?
7.
Why do most desktop computers have a magnetic hard disk drive and a solid state drive instead of just solid state?
Using just solid state would cost much more and you can get higher storage capacity by including magnetic hard disk.
Magnetic.
Whole sector/block is read in one go by the read/write head/
What is a reason for a school to allow teachers to access the school network from their home?
Teachers can access resources on the school network to allow them to plan lessons at home, teachers can teach lessons from home if they are not able to get into work if they have travel difficulties. Teachers can also access electronic copies of students work so they do not have to carry marking home.
What is a reason for a school to not allow access to the school network from home for teachers?
Data protection issues for example if the school may not want potentially sensitive student information to be accessed outside of school. To help teachers have a work-life balance. Increased security risks as teachers may not have fully protected computers and if they dont have an antivirus then it could cause issues for the school network.
What can networks do?
Increase available storage.
Difference between PAN and lan.
you have to cover both to actually state a difference. For example PANs are centred round one person whereas LANs cover a limited geographical area/ larger area. Or one person v more than one usually.
What is used to make a payment securely when purchasing goods from a website?
HTTPS.
In Von neuman what stores the things in the main memory?
Bit patterns.
What is blagging?
This is where a victim is tricked/persuaded by a fraudster to give their details or payment information for a false reason/purpose.
