These are bills for things like gas, electricity and water. Sometimes these are included in the rent : check your tenancy agreement carefully. If you are not sure, ask the landlord/agent whether bills are included. If the bills are not included in the rent then they will need to be paid separately, on top of the rent.
Usually in shared accommodation you all agree between you to pay an equal share of the bills. However, this can get complicated. Some utility suppliers will only put a contract in one name. This means that one person has made a contract with the supplier and they are responsible for the bill. If the others don’t pay their share, the person named on the contract still has to pay the supplier. Even if you move out , you could still be pursued for the bill by the supplier.