I want to accept ethereum from a crowd for selling something from my webpage. I want each individual to send ethereum on an assigned receive address. Is it possible to assign separate ethereum address to each individual.
This is possible. You need to generate a new address for every user and keep track of this private key. However, the question is if this is handy. What might be more elegant is creating a contract for this and have every user send their ETH to this contract, but by tagging their transaction with an ID (or track via the address who sent the transaction). Like this you do not have to create a lot of ETH addresses.
Also a warning: if you create a lot of ETH addresses and want to extract these funds, you are going to pay a lot of GAS for these transactions (gas=transaction costs in this case). You can make this much cheaper by writing a contract for this.