Answer by Ztyx for When should I use typedef in C++?

typedef allows to not only have an alias for complex types, but gives you a natural place to document a type. I sometimes use it for documentation purposes.

There are also times when I use an array of bytes. Now, an array of bytes could mean a lot of things. typedef makes it handy to define my byte array as "hash32", or "fileContent" to make my code more readable.