A series in baseball terminology refers to two or more consecutive games played between the same two teams.

Historically and currently, professional baseball season revolves around a schedule of series, each typically lasting three or four games. In college baseball, there are typically midweek single games and weekend series, with all conference games in series of three games, with the second and fourth rounds of the NCAA Division I playoffs being best two out of three game series. These series are often geographically grouped, allowing teams to visit adjacent cities conveniently. This is known in baseball as a road trip, and a team can be on the road for up to 20 games, or 4-5 series. When a team hosts series at home, it is called a homestand.

The "series" schedule gives its name to the MLB championship series, the World Series

World Series

The World Series is the annual championship series of Major League Baseball, played between the American League and National League champions since 1903. The winner of the World Series championship is determined through a best-of-seven playoff and awarded the Commissioner's Trophy...

The record for the longest series was set in 1904, when the St. Louis Browns

Baltimore Orioles

The Baltimore Orioles are a professional baseball team based in Baltimore, Maryland in the United States. They are a member of the Eastern Division of Major League Baseball's American League. One of the American League's eight charter franchises in 1901, it spent its first year as a major league...

 played the Detroit Tigers

Detroit Tigers

The Detroit Tigers are a Major League Baseball team located in Detroit, Michigan. One of the American League's eight charter franchises, the club was founded in Detroit in as part of the Western League. The Tigers have won four World Series championships and have won the American League pennant...

for 11 consecutive games.