In spanish there are a few more tenses compared to english.
Both words (fueron, and iban) come from the same verb (ir) conjugated for the pronoun THEY (ellos).
We would use "fueron" (past tense) for an action that happened once in the past (They went to the movies last friday).
The use of "iban" is a bit different; this tense would be like the english "I used to...(verb)", in this case "We used to go to the movies". Meaning that this action happened several times in the past.
