If you tell a story from different viewpoints, it's the same as getting inside several characters' heads. At least, with my morning head on, that sounds right!
Although... I guess it's all in the style. Consider this:
Sarah felt very tired. I need coffee, she thought.
When Jane arrived, Sarah was happy to see her.
Jane noticed the dark shadows under Sarah's eyes. She's not sleeping properly, she thought.
"Hi!" Sarah said, trying to remember if she'd fed the cat.
The cat meowed. It was hungry and bored.
Is that omniscient? Or is it from different POVs? I think it's from different POVs. I think omniscient might be more like this:
Sarah felt very tired. She made herself a coffee to wake up a little.
When Jane arrived, Sarah was happy to see her.
Jane noticed the dark shadows under Sarah's eyes. She guessed that Sarah wasn't sleeping properly.
"Hi!" Sarah said. Her mind, however, was on other things – whether or not she'd fed the cat.
The cat meowed. Sarah hadn't fed it or paid it any attention for two days.
I think those might be rubbish examples, but it kind of helped me!
And now for more coffee...