You use a password to authenticate your identity

Security questions are one example of a challenge-response test.

Captcha is given to show that your eyes work properly.

Captcha works because there is no software that can read the letters displayed and enter them

A thing you can do to secure your password is write it down on a piece of paper and keep it in your pocket.

A strong password is something that can not be easily guessed.

The name of a person or your date or birth is a good and strong password to use.

Telling your friends and family your password is a good way to keep your password secure so if you forget it, you can just ask them.

Encryption of password is a good way to secure it so no one else can access or read the password.

Some websites have the feature 'Remember Password'.
This should be used on any public and private computer.