The giants are know like that due their large size, and they keep growing during their whole lives -as long they have fullfiled their dietary needs-. However they seemed to be adapted for the times of prehistoric megafauna, and the desaparition of many of the larger animals meant a colapse in the Giant population, from what they never recovered, before the Neolitic age.
Since then, they adapted their diets to smaller animals, and largely, trees, stones and some kinds of dirt -they digestive systems are capable of extracting many vitamines from these elements, but it isn't an ideal diet-, and it's said depending of a giants diet, how they skin will look.
However, due this adaptation in general it's very difficult to giants obtain the needed energy, so they doesn't move much, and in general are malnourished, which avoid giants to live in large social groups, wandering alone or in small familiar groups.
In general, the giants are known for being slow thinkers, but there are exceptions, and while they didn't developed an advanced material culture, some giants did, mostly from observation and adoption, take some cultural behaviors of other peoples.
The domestication of cattle was an important advance, and if the giants couldn't raise their cattle, often they learned to demand -or ask- for food from the smaller peoples.
When they did have the energy and wheren't thinking in how hungry they where -the giants are allways hungry-, they liked to spend the time in their prefeered hobby: to throw stones, build monolites and crude stone walls, throw stones at each other, dig ditches, flattening hills and making mountains: they called this hobby landscaping.
Being organized in small familiar units, there didn't existed giant countries or states, but some "giant lands", where giants wandered, as was the Gorbegea peninsula, the Titanizk mountains and Dargoina in Aels, for example.
Despise of that, sometimes other powers used Giants for their own interests, as the Silvan Elf empire of Malvor, and during the Great Wars of the Power, the demons gained many giants for their cause... but much more, remained only worrying for their hunger and landscaping.