What is Their Main Difference?
While both 'to' and 'into' are prepositions of motion and direction, they are completely different. The main difference between them is that 'to' used to show direction of a particular position while 'into' is used to show that as a result of an action something is inside a frame.
'To' is a preposition that is helps talking about action, motion, and direction. We use it to show that there is movement from one location to another.
He took her
'Into' is used to show movement that results in being enclosed by something. Note that 'into' is interchangeable with 'in' when we want to talk about movement and direction. Have a look:
We cannot replace them with each other as it will change the meaning into something that is not understandable or to a completely different meaning. Have a look:
Here, the subject ran from one place towards to store and may not have entered the store.
Here, the subject ran inside the store and was enclosed by the building walls.