[jkeyzer]

A compiler turns human readable code into a instructions that the microprocessor can understand.

You write a program in assembly language, then you run the compiler on that file and it spits out an .s19 file, which you then upload into the processor's memory.

The reason we use compilers is because if you had to write your code in 0's and 1's it would be very confusing and take forever! Assembly language is pretty low level but it's easier than writing to the processor directly.

A high level language like 'C' or Java makes it a lot easier to write programs because it has a lot of routines built in so you don't have to reinvent the wheel. But if you are trying to make a program run very quickly and efficiently (and access the hardware directly like hardware guys like to do) sometimes you are forced to write in a low level language like assembly.