فَتَحَ حَامِدٌ الْبَابَ
Hamid opened the door.
يَفْتَحُ حَامِدٌ الْبَابَ
Hamid opens the door.
In these two sentences, فَتَحَ is past, while context gives يَفْتَحُ a present reading. The core meaning “open” remains; in a future context, the same فعل مضارع form can carry a future meaning.