Rotowire
In short
RotoWire is an American company based in Madison, Wisconsin, that provides news and data for fantasy sports and online betting.
In plain words
The company creates updates and statistics for people playing fantasy sports games. They supply this information to many large websites like ESPN and Yahoo! Sports.
A simple example
A fantasy football player reads a RotoWire update to see if a star player is injured before setting their team lineup.
Why it matters
It acts as a major data provider for the entire fantasy sports industry. Many of the biggest sports platforms rely on their real-time information to serve their users.
Easy to mix up
Do not confuse it with a single sports news site; it is primarily a data provider for other major platforms.