The role of Animation/Action in moving bones

When you look at the different examples we have in animation_xxx, there’s always the need to keep some Action in the Dope Sheet if you want your example stills Ok … it’s not clear the role it has. Do you have explainations for it ?

for those who discover Armory, in general we can define a series of various states in which the Character/Armature/Bones/Mesh could possibly exist in our scene/game and that’s the case with Dope Sheet/Actions tools we have in Armory/Blender.
Next, we set the events/actions/properties/values… in which the Character enter and exit of a state, what we call generally a “States Machine” in the literature, and could be represent with something similar to a flow chart.

Out of scope in relation to this question: for those who want to know more, here you reason using well known states which is not always possible, for example if an infinity of your Character’s behaviors is possible at each step. In this case you have IK (Inverse Kinematics) to do it. See here explanations on what you can use in Blender, that is the Pose Mode, and you would like to find/reuse in Armory when in that case with IK