The bus network in Barcelona is very extensive and almost all services cover the major areas. The buses run daily from 6:30am till 10:00pm. Single tickets are available with the drivers and cost about €1.10 and travel cards must be validated in the machines when you board the buses.
There are 16 night bus routes through the city to some limited destinations that run daily, every 30 minutes or so from 11:00pm till 4:00am and require separate tickets.
There is a shopping service, TombBus, that runs every 7 minutes on weekdays and every 15 minutes on Saturdays during summers, between Placa de Catalunya and Placa Pius XII. From Monday to Friday, it runs from 7:30am to almost 10:00pm. On Saturdays it runs from 9:30am till 9:45pm. A single ticket costs about €1.35.
Apart from these, there are several multi-ride tickets and passes also available costing somewhere between €6.00 to €100.00 depending on the number of zones, modes of transport and the validity period.