Is GDB just for bug hunting?

[Jason Long]

Hello,
I have some questions and I'm thankful if someone answer to them clearly:

1- I want to know, is GDB just useful for bug hunting or a security researcher can use it to find vulnerabilities too?

2- Is bug vs vulnerability? Consider someone that find an exploit in a program. He/she found a bug or Vulnerability? He/she used a debugger to find that or any special tool?

3- A debugger could be a Vulnerability researcher or vice versa?


Thank you.