Types are a nuisance
Types are a nuisance in C. Your data usually consists of strings, real values, and integers. The integers are usually ultimately an index into some sort of array.

So really you need only three basic types. However you also build structures out of those types, and make pointers to them. Finally because of machine efficiency reasons various representations are used - flaots and doubles for reals, shorts int and longs for integers. In themselves these aren't too much of a problem, they can be mixed and matched. Incompatibilities arise when you pass them by indirection. A short * won't mix with an int *, even if the underlying machine representation is the same.