In Spanish, the Present Tense indicates the current time; however, sometimes there are actions or states that are not in the present.

habitual present -it happens habitually.
Juan se afeita todos los días.
Juan shaves every day.

current present -the actions is happening right now.
Mis amigos están en clase ahora.
My friends are in class right now.
Estoy escribiendo.
I am writing.

universal present -the statement is always true.
El perro está siguiendo al gato.
The dog is chasing the cat.

present by future -it will happen in the near future but the verb is in the present tense.
Nos vamos de vacaciones en julio.
We are going on vacation in July.

historical present -the action was in the past but it´s told in the present time.
Ayer comí pastel y, cuál es mi sorpresa, que veo una mosca dentro de él.
Yesterday I ate a piece of cake, and to my surprise I see a fly inside it.