what is pointer in C and C++
Simple int and float variables operate pretty intuitively. An int variable is like a box which can store a single int value such as 42. In a drawing, a simple variable is a box with its current value drawn inside.
A pointer works a little differently— it does not store a simple value directly. Instead, a pointer stores a reference to another value. The variable the pointer refers to is sometimes known as its "pointee". In a drawing, a pointer is a box which contains the beginning of an arrow which leads to its pointee. (There is no single, official, word for the concept of a pointee — pointee is just the word used in these explanations.) The following drawing shows two variables: num and numPtr. The simple variable num contains the value 42 in the usual way. The variable numPtr is a pointer which contains a reference to the variable num. The numPtr variable is the pointer and num is its pointee. What is stored inside of numPtr? Its value is not an int. Its value is a reference to an int.