Creating an account allows you to store your settings, so that they will apply the next time you log in. It also allows you to record your performances and have a look at them in graphs. This even allows you (if you wish) to compete with other players.
If you have any questions about the terms of use and the data policy, see here.
validate
If you already filled out the fields and received a code by mail, you can validate your account here.
Don't forget that you have one hour of time only to validate your account ! After this, you must fill out the fields again.