One button or two for sign up and log in?

1. What is better log in or sign in?
2. Why is sign up bigger than sign in?
3. What is different between sign in and sign up?
4. Which button is clicked to register to a new account?

What is better log in or sign in?

Using the term 'login' means that at a glance the user can instantly tell the difference between 'Login' and 'Sign up'. By using 'Sign in' the user has to take a second or two to read the words to identify between the two and there's more chance of them clicking the wrong link.

Why is sign up bigger than sign in?

A person has to be a member of the site before they can log in. Thus most websites promote the button for signing up more than the login button, making it easy to actually sign up.

What is different between sign in and sign up?

What is the difference between sign in and sign up? Sign In: you already have a user name and password that you must provide for access, Sign Up: You need to register to get a user name and password to join the organization or website.

Which button is clicked to register to a new account?

Login | Register: This would explain clearly what the button's function is.