We have many of them of in Barcelona. You can find specific ones, like all computer, cloth or hardware related.
The most famous are “Alcampo” (a French mall), “Carrefour” (also French, it’s old name was PRYCA but it was bought by them) and IKEA… and I guess this one needs no explanations. They are everywhere.
The malls are related to one of the most infamous Spanish traditions. Have breakfast, lunch and dinner for free while you enjoy the aircon and play some videogames.
Alcampo and Carrefour are similar, both sell the same. IKEA sells furniture, which by the way, it’s a pain in the ass to do it yourself.