The Preterite Tense is very often called the simple past tense or in Spanish Preterito Perfecto Simple.  This is the first past tense and is used to describe an action in the past which has happened once.   Very often there is a timescale used with this tense such as yesterday (ayer), last week (la semana pasada) or even the word once (una vez).  Note there are two different patterns.  One for AR verbs and another for ER and IR verbs.