Computer Science
Define a 'Library'
A collection of pre-written code, classes and procedures that have been tested
Give benefits of using libraries
- It's saves more time as you don't have to constantly write everythin from scratch
- They're reliable as they've already been tested so are unlikely to have any errors
- Pre-compiled, so they're can run quicker & reduce execution time
Give drawbacks of using libraries
- Making changes to libraries can be very hard to implement or even impossible
- You don't know how efficient the library routine is
- You don't know how long developers will continue to maintain the library
What does a 'Linker' do
It combines different code files & libraries into a single executable program
What is meant by 'Static linking'
Copies all the code from libraries that the program uses into the final machine code. This results in a larger file size
What is meant by 'Dynamic linking'
Where programs use shared libraries, these libraries are only in the machine code whilst the program is running. This reduces the size of the executable file
What does a 'Loader' do
A part of the OS that loads executable programs into memory ready to be run
Give a disadvantage of dynamic linking
It can cause issues if a library has been removed or is incompatible