What links here
From PCGamingWiki, the wiki about fixing PC games
For the purposes of PCGamingWiki's taxonomy, 'DLC' specifically refers to medium size chunks of additional game content such as maps, levels, quests, new gameplay mechanics etc. that is normally created in addition to the game, paid for and downloaded, but less substantial than an 'expansion pack'.
Mass Effect 2
's 'Lair of the Shadow Broker' is a purchaseable story mission with voice acting and new gameplay mechanics.
's '3C3C1D119440927' includes three new battle arenas, three new outfits, as well as a new short side-storyline.
This category could be called 'Extra gameplay', but DLC is a much more familiar term to most gamers.
Expansive Expansions (Expansion Packs)