The definitions, for those who aren't familiar with C, are as follows:
return-type function-name( type1 parameter-name1, type2 parameter-name2.... );
The types are in C style, so that their format is 'base-type [pointer-markers]'. 'Pointer markers' are simply asterisk characters (*), and the number of markers indicates the pointer depth. No markers means that the parameter is not a pointer, one means that it is a pointer to a base-type, two means a pointer to a pointer to a base-type, etc. [For details on the base types used, see Types]
For Win32 Unicode functions, the function name gives only the base name. The unicode version of the name will have a 'W' (which presumably stands for "wide-character") appended and the ansi version will have an 'A' appended.