Comparatives are used to compare two things, and show differences in degree. They are formed by adding "-er" to adjectives or adding "more" before them.
Adjetivos comparativos y superlativos
Comparative and Superlative Adjectives
Los adjetivos comparativos se utilizan para comparar un sustantivo con otro sustantivo. Los adjetivos superlativos se utilizan para comparar tres o más sustantivos.