What is it called when you link a word to another word?

I was wondering what is it called when you link a word to another word for example: Yahoo – internet – computer – computer desk – wooden – tree – forest – natural – muesli – supper market – shopping center – wall mart – lots of jobs – no jobs – recesion. saying that I think that Yahoo is connected to the recesion. But anyway is there a name for that? Thank you.