The main objective of having Twitter account is to be able to stay connected with people within the social networking community at any moment in time. Inasmuch as Twitter is a social network platform where people of same interest share ideas and thoughts, not everyone is given access to the use of Twitter unless one has created a Twitter account and has logged in.
To login to your URL Twitter is to sign in your username and password. It is only you and Twitter who remembers the password that you have assigned. In the event that you forgot your password as you log in, Twitter will reset your password and send the information to your email address.
Login allows Twitter users the access to the Twitter account. You can actually do everything inside Twitter once you are logged in. You can make changes to your account settings, change background designs, update your photo, etc. It also allows you to make quick replies to messages sent to you by followers either through @reply or direct message. You will observe that if not logged in, you are forwarded to the log in window before you can follow or view your followers.
To be able to use Twitter is to have an Internet connection or a mobile phone. If you already have a Twitter account on your mobile phone and would like log in using the web, Twitter will get you signed up on the web once you have provided them with your mobile phone number.