Third-person POV varies by how much the narrator reveals to readers about the interior lives of other characters beyond the protagonist. The spectrum stretches from limited to omniscient. A third-person limited POV means the reader is limited to what the POV character knows. The Harry Potter series is a famous example; readers only know what Harry knows. This POV is popular in many murder mysteries, where readers find clues along with the detective and discover the killer only when the detective does.
Handling the third-person limited POV can be tricky for writers. A mistake I often see as an editor is when the POV character tells the reader what another character is thinking or feeling when the POV character has no way of knowing that. Often the problem can be solved by having a character do or say something that allows the POV character to draw a conclusion. (Other solutions are more inventive; in the Harry Potter series, the invisibility cloak and Pensieve are clever devices that allow Harry to witness events and experience the memories and feelings of others in a believable way.)
In the third-person omniscient POV, the narrator can show readers what all the characters are doing, thinking, and feeling, even if the POV character doesn't have this information. Some examples of this POV are Middlemarch and Anna Karenina. Omniscient narrators work well in epic stories or ones with many characters. A drawback to this POV is that readers are told too much rather than making their own discoveries based on what characters say and do.
If a writer wants to hop into the minds of multiple characters, then often an omniscient narrator is established first, as in Elizabeth Strout's novel Amy and Isabelle. Otherwise, the convention is to wait for a scene or chapter break before switching to another character's point of view. If the writer hops between multiple points of view in the same scene, it can be jarring to readers.
Third-person POV also varies by how subjective or objective the narrator is. In a subjective point of view, the narrator can see inside a character's mind and shares those thoughts and feelings with the reader. In an objective POV, the narrator is like a camera, just recording actions. The effect is a detached, unbiased report. Examples of third-person objective POV are the Hemingway story "Hills Like White Elephants" and Tom Wolfe's The Right Stuff.
Even though third-person is the most common POV in fiction, it's far from boring. Writers can experiment with limited or omniscient knowledge and objective or subjective narrators.