Functionality
Typical toolkit functionality included editing extensions, such as commands to renumber a program, perform block line deletions and so on, facilities to make structured programming possible, and additional keywords to perform new functions. In the case of the latter, these new functions often allowed the programmer to easily access the computer's graphics, sound and other hardware which was often partially or completely unsupported in the early BASICs. This would have otherwise been achieved by arcane usage of PEEK and POKE commands and machine language routines.
Read more about this topic: BASIC Extension