When you write in 3rd person limited, you are limited to one character's Point Of View per scene. The reader sees everything through that character's eyes, and shares the character's thoughts and emotions.
Lisa walked into the room and sat down. She pointed the remote at the TV. Two women appeared, standing behind a counter. One was holding some sort of kitchen gadget while the other looked like she was having an orgasm. The scene cut to a roomful of women clapping. Lisa wanted to puke.
In the above example we were in Lisa's mind, not the mind of an omniscient narrator. A clue here is "some sort of kitchen gadget". Lisa didn't know what it was, or didn't care. An omniscient narrator would know. An omniscient narrator might have said, "One was holding a handy-dandy-slicer-dicer while the other looked on with approval."
The narrator might not have been that bland about the Lisa's reaction to the other woman, but an omniscient narrator would probably not have presented the orgasm comparison. That was Lisa's disgust showing through, wasn't it?
Look at the passage again. Have you formed an impression, just from this short paragraph, of how old Lisa is? Do you expect that she has, perhaps, just come home from school? I doubt if you pictured Lisa as a fifty-five year old grandmother about to watch some television before turning off her light.
I don't mean to be sexist nor do I want to descend to stereotyping. I'm pointing out, though, that if you write in 3rd person limited, and put yourself right inside the mind of your character, you get a head start at engaging the reader. And reader engagement is your goal. You want the reader to care about and empathize with your characters.
Tired and disoriented, Jason slumped to the ground. Maybe waiting for sunrise was the best idea, despite the cold. He glanced up, The clouds had dissipated. The Big Dipper greeted him like an old friend, pointing to Polaris, the North Star. With renewed hope, and the stars to guide him, he pushed himself to his feet and headed north. If the sky stayed clear, he'd hit the interstate before morning.
The above is in Jason's POV. Maybe waiting for sunrise is his thoughts, not a comment from an omniscient narrator. Similarly, it's Jason realizing that he could now find the interstate highway, not the omniscient narrator passing info to the reader. Notice that the writer didn't have to use Jason wondered and Jason realized. Those filter words aren't needed in 3rd limited POV. Also, no italics or he thoughts are required for the reader to identify a POV character's thoughts.
A good writer can accomplish reader engagement while writing in omniscient narrator POV, but I suggest that you will have an easier time — and find it more fun — to write in 3rd person limited.