Trolls

Tolkien Trolls
Large to extremely large, created by Morgoth by the corruption of some unknown humanoid race (possibly Orcs). Stone trolls may not have been bred from other creatures but rather been animated stone. They were intended as a mockery of Ents. Most had just enough intelligence to speak languages. Often trolls were kept chained as if they were slaves and animals by Morgoth or Sauron or other more intelligent creatures aligned to them. Trolls were created before the Sun and for most, if caught in its light would be turned to stone. After Sauron's destruction, some committed suicide. Tolkien Trolls lack many of the traditional troll traits. Notable they are not known to guard bridges nor have an affinity for riddles. Some depictions of Tolkien Trolls are more ogre-like, such as in the 1977 TV movie, The Hobbit. Their habit of eating intelligent humanoids is shared with traditional ogres.

Stone-trolls spoke perverted form of Westron spoken with a cockney accent. Notably, they had names and surnames that were very unusual in Middle-Earth such as "Tom", "Bert", and "William Huggins" ('Bill'). Stone-trolls, at least some of them in the third age, lived free independent lives in an area known as the Trollshaws, enslaved to no other of Sauron's creatures. The Trollshaws had a distinct road through it, constructed by the Trolls. They preyed on travelers that used it. Stone trolls may not have been bred from other creatures but rather been animated stone.
Cave-trolls, presumed to be a type of stone-troll, had toeless feet, and were adapted to underground living. Their extremely tough green scales and hide were nearly impervious to bladed weapons, even magical ones. Known only to dwell in Moria and be enslaved to orcs. They may have been even less intelligent than other trolls.
Snow-trolls are white and dwell in cold places. It is unknown if Snow-trolls could survive sunlight.

Olog-hai were "strong, agile, fierce, and cunning" trolls created by Sauron. More so than other trolls, they were suspected of being bred from Orcs and may in fact be from a different humanoid than other trolls. Their higher intelligence (for trolls) being the source of the suspension of Orc heritage actually seemed to cease after the destruction of Sauron. They spoke the Black Speech. Most notable, they could survive sunlight, although the still hated it.
Hill-Trolls, gigantic and very dangerous Olog-hai. They used sophisticated weapons and armor. Hill-Trolls could survive sunlight, but hated it, as did all trolls.
Mountain-trolls were large and extremely strong Olog-hai that carried the great battering ram Grond used to shatter the iron gate of Minas Tirith. Also could survive sunlight.

Half-trolls/troll-men may or may not have been trolls. They were human looking.

In some cases these may be considered giant humanoids.

The only common trait most trolls of any mythos share is their unnaturally fast regeneration, in some this may be so fast you need special methods to kill them. However, even this is not always present. Another trait trolls often have in common is that they're far more ugly than the other demi-humans such as ogres, orcs or goblins.

Note that like with many fae from folk lore, the name alone should not be used to determine if the things are trolls. Rather, look at the traits they have. For example, Tolkienin trolls are better described as ogres.