For questions concerning D&D Adventurers League rules and play. Adventurers League is an official D&D 5e organised play format.
Adventurers League is Wizards of the Coast's official D&D organized play program for 5e. (For 4e organized play please use the dnd-encounters tag.)
The D&D Adventurers League is an ongoing official organized play campaign for Dungeons & Dragons. It uses the fifth edition of the Dungeons & Dragons rules, and features the Forgotten Realms setting. You can play D&D Adventurers League games at any place that features adventures bearing the D&D Adventurers League logo. You can create a character and bring that character to games anywhere D&D Adventurers League is supported.
Most D&D Adventurers League games are public, in-person play events. Typical venues for these events are game and hobby stores, conventions, and public-accessible game day events.
Adventurers League originally encompassed three programs: Encounters, Expeditions, and Epics. Confusingly, Wizards' entire organized play program during 4e was also named D&D Encounters, thus the dnd-encounters tag. Circa 2016 the Encounters and Expeditions names were dropped; AL play still consists of either ongoing campaign play from hardcovers or of one-session modules published by WotC.
Consider reading the Adventurers League rules documents before asking questions about AL-specific rules; there's a good chance that the topic will be covered there. The Downloads page on the Adventurers League website contains links to the latest versions of these resources on DMsGuild, including the Player's Pack and the DM Pack.