- Computers have memory and file storage.
- Short-term and long-term memory.
- Loading files from the disk is long-term memory.
- A variable in a program is short-term memory in the processor.
- If you have two programs, once program can save a file to disk and the other program can pick it up
progA and progB
- However if
progA writes something to memory, progB cannot access it.
- OS’ place walls in between the programs.
- Very important for programmers to know where these are being stored and whom has access to what.
- OS’s also allow placing two programs into the same process.
- They then get to share memory.
- Instead of separate processes, they are run on separate threads.
- A process can have multiple threads.
- Can execute code at the same time in parallel.