What is the perfect tense and how is it used?

The perfect tense makes a distinction between the perfect tense (I have gone out) and the simple past (I went out). 

The form constits of the verb haber:

he

has

ha

hemos

habéis

han

The following verb will then follow with an ending of +ado (ar verbs) or +ido (er and ir verbs).

For example: He has spoken to Maria.

Ha hablado con Maria.

The use of the perfect tense will mainly be used based on what someone has done today. E.g. Yesterday I went. Today I have been.

However, it can also be used in terms of what you have done over your life time. E.g. I have been to America. - He ido a America. But when you express a specific time in the past you would use the simple past. E.g. I went to America last summer. - Fui a America el verano pasado.