How can I get the access token?

Could you elaborate on the process of acquiring an access token, please? I'm particularly interested in understanding the steps involved, from initiating the request to successfully obtaining the token. Are there any prerequisites or specific credentials required? Additionally, what kind of information should I expect to provide during the process? Is there a standard format or structure that I need to adhere to? Understanding these details will help me navigate the process more efficiently and securely. Thank you for your assistance in clarifying this matter.