The Trinity refers to the three-fold nature of God (God father/God Spirit/God Son).
The best depiction of the Trinity is found in Matthew 3:16-17:
As soon as Jesus was baptized, he went up out of the water. At that moment heaven was opened, and he saw the Spirit of God descending like dove and lighting on him. And a voice from heaven said This is my Son, whom I love; with him I am well pleased.
This doesn’t mean there are three distinct separate Gods, but shows the triune nature of the Godhead.
The Bible clearly represents God as One. Deuteronomy 6:4 says, “Hear, O Israel: The LORD our God is one Lord.”