Not necessarily, and ideally this isn't the case.

Although it is possible to set up a single receiving address to receive payments to, it causes a number of issues. First of all, it greatly reduces your privacy, since every knows that address belongs to you and can see exactly how much money you have received on it. Secondly, it makes automating payments near impossible, since there is no way to reliably tell which customer made which payment without them manually sending you details of it, and even then, they could simply send details of someone else's transaction.

Almost all payment processors, merchants, exchanges, and so on, will generate at least a unique address for each customer, and ideally a unique address for each transaction.