When we talk about the difference between two of them, the most noticeable difference is that the bolt action rifle request from a user to operate the bolt manually to extract the expended cartridge before manually inserting and preparing the next round to be fired.
A semi-automatic rifle eliminates the need to manually cycle the bolt yourself, enabling you to fire the next round only with the pull of the trigger. Besides that essential distinction, maybe the best describing word for these various types of action is versatility. A bolt-action rifle can be chambered for any cartridge that an AR/M16 style rifle can use, and hundreds that an AR-15 cannot.
Although bolt guns are older in design, their simple system for loading and ejecting the ammunition, make them more robust than the more complicated semi-auto rifles.
In addition, like with any semi-automatic firearm, we can find a host of weapon-induced or shooter-induced malfunctions. While some AR-style rifles are very accurate, no semi-auto can ever match the inherent accuracy of a bolt gun.