Unit 4 Exam Questions With Answers Review Questions & Answers (Rated A+)

One function of a modern PCs operating system is multi-tasking. This allows two or more programs to be open at the same time. Describe how multi-tasking works. {Ans: When a program is opened, the program instructions are copied into RAM (1) along with any data/files that the program needs (1). Other programs can also be opened and copied into RAM (1). The operating system manages for one of the programs to get a small amount of CPU time (1). When it has this time, the instructions are executed (1). The CPU will then make the program wait whilst another program gets CPU time (1). As this happens very quickly, the user will experience one or more programs appearing to run at the same time (1) even if there is only one CPU (1).}A website developer has said that they are concerned about two possible attacks on their website which are denial of service (DoS) attacks and SQL injection. Describe how a denial of service attack works. {Ans: A computer will send a huge number of network packets / requests (1) to a server (1). The computer will be able to send more of these than the server can