When we talk of Gmail password recovery requirements, we are making reference to things you must have, before Google can help you recover/reset your password(in case you forget your Gmail password).
Firstly, for you are to recover a Gmail password, you need to answer the test questions correctly. These are simple questions, whose answers youll have provided at gmail.com when signing up for the service. Answering the questions correctly assures Google that you are indeed the owner of the Gmail account whose password you are trying to recover.
Secondly, for you to recover a Gmail password, you need to have an alternate email account where the recovered password can be sent.