Bot refers to the bottom lane on Summoner’s Rift, one of the three primary lanes in the game. This lane is usually occupied by an ADC / AD Carry and a support champion. The ADC focuses on dealing consistent ranged damage, while the support provides protection, utility, and wave control during the early stages of the game. Because two players share the lane, bot side has a strong influence on early dragon control and mid to late game team damage.
The bot lane is also strategically important due to its proximity to the dragon pit. Coordinated play, proper vision, and timely rotations allow bot duos to secure early objectives and gain advantages for their team. As the match progresses, bot lane champions often become key contributors to overall DPS and play a major role in deciding teamfights.
Although the term “bot” can also refer to AI controlled characters in other contexts, within Summoner’s Rift gameplay it specifically means the bottom lane position.