The screen says no disc even when I put a DVD in

Now in the market, laptop will be produced without disc drive and even some PC have no this optical drive too. Disc drive is a component consuming lots of room. To increase the portability of laptop and saving cost, the producer will choose to discard this component.
But it doesn't mean that you can't play DVD on your PC. You can use an external DVD driver and connect it to PC with USB cable.
BTW, here is the guide to solve problem of no disc error if you need.

First, try another DVD disc on your DVD player that can be played on this player before to see if it's the DVD player's issue. If the disc can play, then it's probably the disc' s problem.
In this case, how to solve the "no disc" problem? Use a lint-free cloth and some denatured alcohol or water to clean the disc and remove any dust or smudges that may prevent the player from reading it properly. Reinsert the disc into the player and press "Play" to see if cleaning the disc fixes the "NO DISC" error.
If the disc is still can't be played, a more expensive option is to use a commercial lens cleaning disc. A lens cleaning disc looks like a DVD with tiny brushes for the lens; it is inserted and "played" like a DVD for the time specified in its user guide.

Dear friend,
Pls clean ur dvd palyer lense or replace ur lense