Point of view describes the perspective from which the story is told
First person uses "I" and the story is told from one character's perspective, this can be limiting but can also feel more personal to the reader, works effectively in thrillers.
Second person uses "You" and is the least common POV
Third person limited uses "He said, She thought" and is when everything is seen through the main character's eyes in the past tense, there aren't any shifts at any other time to other character's thoughts or emotions.
Third person subjective multiple-viewpoint is when more than one character tells the story at a time. Shifting to another character's viewpoint is most often done in a new chapter, or by some how letting the reader know the character's have switched viewpoints by inserting an obvious break in the story line.
Third person omniscient is when the author takes a panoramic bird's eye view of the character's in describing the overall picture. It isn't shown through the eyes of any one character but an invisible, all-knowing, all-seeing narrator. This works best in a story with a complicated plot and multiple characters.