Dev - C++ - Understanding Pointers in C++

What is a pointer in C++ and how does it differ from a normal variable?
Explain the concept of pointer arithmetic in C++. How is it used and what precautions should be taken?
How are pointers utilized in dynamic memory allocation in C++? Provide examples.
Discuss the difference between pass by value and pass by reference in function parameters, using pointers.
What are null pointers in C++? How are they used and what potential issues can arise from their misuse?