Lists are a great way to group and organize the people and businesses that you follow on twitter. This is similar to Facebook's "group" feature. You are capable of making a list of people with interests similar to yoursto keep up with their tweets.
You can also easily group your college friends, organizations, and family members so that you can see only what those grouped individuals are posting.
Lastly, you can follow large amounts of people without cluttering your daily Twitter feed.
How to create a list via Twitter:
1. Go to your Lists page. This can be done via the gear icon drop down menu in the top right navigation bar or by going to your profile page and clicking on Lists.
2. Click Create list.
3. Enter the name of your list, a short description of the list, and select if you want the list to be private (only accessible to you) or public (anyone can subscribe to the list).
4. Click Save list.