In its refined form, Trinitrotoluene is fairly stable, and unlike nitroglycerine, it is relatively insensitive to friction, blows or jarring. This means that it must be set off by a detonator. It does not react with metals or absorb water, and so is very stable for storage over long periods of time, unlike dynamite. But it is readily acted upon by alkalis to form unstable compounds that are very sensitive to heat and impact.
Note that non-nuclear explosives release less energy per kilogram than everyday household products like fat (38 MJ/kg) or sugar (17 MJ/kg); they do, however, release their combustion energy much more rapidly.