AOL, or America Online, is an internet service provider and web portal that was popular in the 1990s and early 2000s. It offered dial-up internet access, email services, and a variety of online content, including news and entertainment. AOL was known for its iconic instant messaging service, AOL Instant Messenger (AIM), which allowed users to chat in real-time. At its peak, AOL had millions of subscribers and played a significant role in bringing the internet to the mainstream. However, with the rise of broadband and other internet services, AOL's popularity declined. Today, it operates as a subsidiary of Verizon Communications and focuses on digital media and advertising.