While this short program is not terribly difficult to understand, it can be extremely tedious and error prone to keep track of the large number of numerical addresses that would be used by a complex program. For this reason, assembly language allows you to give names to memory locations, so that you can refer to the locations with meaningful names rather than meaningless numbers. Names used in this way are called labels . To give a name to a memory location in an assembly language program, all you have to do is put the name, followed by a colon, before the contents of the memory location. For example, you could jump to that location with the command JMP Loop .
Memory locations can be use to hold either instructions or data .
Labels are useful in both situations. Labels for instructions, on the other hand, are mostly used in jump commands. Here is a version of the counting program that uses labels. It is a directive to the assembler telling the computer to store the next item in location 12. In this case, it means that the Count will be stored in location 12.