what is the type of the value stored in a pointer
Pointer (computer programming) In computer science, a pointer is a programming language object, whose value refers to (or "points to") another value stored elsewhere in the computer memory using its memory address. A pointer references a location in memory, and obtaining the value stored at that location is known as dereferencing the pointer. As an analogy, a page number in a book's index could be considered a pointer to the corresponding page; dereferencing such a pointer would be done by flipping to the page with the given page number and reading the text found on the indexed page.
Entry point Alternatively, execution of a program can begin at a named point, either with a conventional name defined by the programming language or operating system, or at a caller-specified name. In many programming languages, notably C, this named point is a function called main; as a result, the entry point is often called the main function.