The Avengers can refer to a few different things, but most people mean the Marvel superhero team. Here's a quick overview:

Marvel's Avengers

A superhero team from Marvel Comics, created by Stan Lee and Jack Kirby in 1963 (The Avengers #1). The roster has changed constantly over the decades, but core members include:

• Iron Man (Tony Stark)
• Captain America (Steve Rogers)
• Thor
• Hulk (Bruce Banner)
• Black Widow (Natasha Romanoff)
• Hawkeye (Clint Barton)

The team's motto/call: "Avengers, assemble!"

Marvel Cinematic Universe (MCU) Films

The Avengers franchise within the MCU includes:

• The Avengers (2012)
• Avengers: Age of Ultron (2015)
• Avengers: Infinity War (2018)
• Avengers: Endgame (2019)
• Plus Avengers: Doomsday (2026) and Avengers: Secret Wars (2027) announced for the future

Other Uses

• The Avengers (1998 film) — a spy film based on the 1960s British TV series The Avengers
• The Avengers (TV series) — 1960s British spy show starring Patrick Macnee and Diana Rigg
• Avengers (band) — a 1970s punk rock band
• Avengers (comics) — the original Marvel comic series

Which one were you asking about? I can go deeper on the comics history, the MCU timeline, or a specific character.