That is a very common question. When there were physical certificates you could see the share certificates. Today, there is nothing you can see in your demat account except the account balance. But that is absolutely fine. If your demat account shows the credit of shares then it means that you own the shares. That is proof enough. If you question is whether it is ok not to have physical certificates then the answer is that it is absolutely ok.
You may perhaps be wondering what you have opened a demat account with your broker so what happens if your broker closes shop tomorrow? The shares in your demat account are actually lying with government-sponsored institutions like NSDL or CDSL. These are large institutions that are regulated by SEBI and sponsored by government institutions. Even if your broker closes down, your shares are still absolutely safe.