Planets are all around us, we have been learning about them since we were very little, and we also live on a planet called Earth. There are a lot of planets in space, and most of us know about 8-11 of them. There are planets outside our solar system, and most of them are in other solar systems. The reason I said most is because there are many rouge planets just drifting around in space, which makes them difficult to observe with our eyes, and we have to use special instruments to search them, they are easier to be found by x-rays than heat sensors, as they have very little heat, as planets get heat from their nearest heat producer which is usually a star.
There are many types of planets in the Universe, some made of all diamond, and some made of rocks and soil and water and have what we call intelligent life on them (Earth), while some are made of gas, and have a solid core (Jupiter). There are two types of planets, Terrestrial and Gaseous. Terrestrial planets include Mercury, Venus, Earth and Pluto, these planets consist mainly of solid materials, like rocks, and soil, while gaseous planets like Jupiter, Saturn and Neptune, which consist mostly of gas and are mostly bigger than terrestrial planets.
This is all for today, feel free to comment if you want to know more or what you want next!