The problem with cracked concrete is that, over time, those small cracks can turn into bigger problems. The water that fills them erodes the base beneath the slab and when the temperatures drop that water freezes and expands, making the crack worse. The immediate solution is to fill the crack with concrete repair caulk to stop the water. The long term fix is to patch it with concrete resurfacer.
In either case you’ll need to clean the slab and the cracks first. The concrete resurfacer is mixed with water much like cement but the resulting material is more fluid so it flows into gaps and cracks to level them out. Once it dries the same material can be spread thinly over the whole surface with a squeegee to disguise the repair.