9 Mark Question points

• concurrent = having more than 1 process running simultaneously • each process is a thread • can use multiple cores, each running a different thread • OR single core jumping between processes • concurrent processing allows for multiple processes to happen at the same time • requires record locking - allowing one person to access at a time

• global variable = can be accessed anywhere in code, retained in memory throughout the program • local variable = can only be accessed with the subroutine it is declared in, only stored in memory until subroutine is finished • local variable means we can write self contained subroutines - can be imported/used in other programs without importing global variable as well • global pros: easier to code • global cons: less memory efficient, poor programming technique • local pros: memory efficient, easier to trace • local cons: less easy to code

• explain what a class, object, attributes and methods are • explain: • polymorphism • encapsulation • inheritance • benefits: lots of objects can be instantiated from a single class, reusability, easier to maintain, easier to modify

Decomposition: - splitting the problem into smaller subproblems - solve the subproblems separately and recombine into a solution - divide and conquer - spread the subproblems over different programmers - modules may already solve part of the problem Abstraction: - removing unnecessary detail - using symbols to represent elements - focus on the important elements of the problem - decreases time spent programming a solution - decreases processing power required - decreases memory space required