It is one of the prepositions of our language. It's also a turning-in to get in. It means entering, penetrating, getting in, passing, entering.
Enter : ( prep . ) 1- Indicates a situation or state in the middle of two or more people or things. Example: The eclipse occurred between ten and eleven in the morning. 2- Indicates participation or relationship in a group or situation . Example: I told that boy that there can be nothing but friendship between the two. . 3- Inside, inside. Example : The leopard hid among the thicket of the forest so as not to be seen by the boar that was going to hunt. 4- In mathematics, mark that one figure is divided with the next . Example: Twelve out of three equals four . 5- Indicates equality or comparison . Example: School work we did among the four.