It helps the organelles move around the cell and it is the material within a cell apart from the nucleus.
All organelles, including nucleus, mitochondria, ribosome, and every other organelles are found within the cytoplasm.
I know you just copied this down from your homework, so I'll just tell you in incomplete scentences. The eukaryotic cells have organelles, and an organizd nucleus. The prokaryotic cells (bacteria) have no organized nucleus, no organelles, and cannot specialize.
This is a classic. Think of the nucleus like the town hall. It houses all the information and important things for the cell. The cell membrane is kind of like border patrol (let's imagine this "city" is in Texas). The mitochondria are like the power plants; they provide ATP/energy for cellular processes. Lysosomes are basically the trash-men. They break down waste material so it doesn't build up in the cell. Vacuoles also hold water, so I guess you could think of them as water towers? Never really came up with a good analogy for that one. Vesicles are like the public transport; they get things into and out of the cells. Continuing on this mindset, just think of the rest of the organelles and apply them to random things in a city.