Ask.com is basically like Facebook, twitter, and any other social website. Followers are like your friends on those sites they can see what questions you have been asking and answering recently by clicking on your name. Most people choose to follow someone after they have read their questions and answers and have liked what they have to say and ask. After someone is following you, you can go into your profile and choose to ether block them so they can’t follow you, follow them back so you can see what they have to say or do nothing. In a nut shell they are people who like what you have to say and ask, and just want to see what else you have answered and asked. By the way welcome to ask. :)
When someone follows you (or you follow them) it means they like what you have been posting and want to be able to find new content you post. When you follow someone a list will appear at the top right of your profile page you can click on their icon to get to their profile page and scroll down to see their "recently asked" and "recently answered" content. You can then click on those to go directly to the content posted so you can read it /comment on it :)
Welcome! Followers like what you have to say. It makes it easy to see where they last posted by going to your profile, click the person and the last question. Unlike FB, and Twitter followers on ASK are earned, it takes time. Be an active member and you'll get followers over time. Follow those you like. Don't worry if you don't get many right away! Good luck. Have fun!