Galaxy

Introduction
The Solar System we live in is vast and Spacious and has a World of spectacular astronomical objects that would take eons just to count up it all. Now imagine a system of solar systems, that my pisano, would be a Galaxy. A Galaxy is system of stars, dust, interstellar gas, star remnants, dark matter and more gravitationally bound together in the reaches of space. A galaxy can have billions of stars, star are big, so billions of them is quite the formittable size to imagine in the mind. Our Sun alone, which isn't even considered a big star by astronomical standards can fit 1.3 Million Earths inside of it. The amount galaxies in The Universe is estimated to be Two Trillion Galaxies! To put that into perspective even more, the average human will live for 22 Million seconds, that means if you were to count one star per second in your entire life, you wouldn't even come close to counting them all!. The Universe is often larger than we think. Even just counting all of the stars within a galaxy per second would be impossible in the average human lifespan. Hard to imagine all of these things in Space once being compacted into one Primeval Atom. 
The Galaxies
Even though there are more galaxies estimated to exist than we can count, there are some that hath been named. Here are some of the galaxies we have named. The Draco Galaxy (Draco dwarf), The Milky Way Galaxy (our galaxy), Andromeda Galaxy, Cartwheel Galaxy, Comet Galaxy, Fireworks Galaxy, Medusa Merger, Whirlpool Galaxy, Cigar Galaxy, Sombrero Galaxy, Pinwheel Galaxy, Sunflower Galaxy, Backward Galaxy, Large Magellanic Cloud, Virgo Stellar Stream, Canis Major Dwarf & Baby Boom Galaxy.
Types of Galaxies
Not all galaxies look the same. There are four different types of galaxies in The Universe. The Four types of galaxies are Elliptical Galaxy, Spiral Galaxy, barred spiral Galaxy & irregular Galaxy. Our Galaxy, The Milky Way Galaxy, is itself a Spiral Galaxy. A Spiral Galaxy is, according to The Oxford dictionary, "a galaxy in which the stars and gas clouds are concentrated mainly in one or more spiral arms.". A Spiral Galaxy is probably the most recognizable galaxy out of the rest. Other example of Spiral Galaxy are Andromeda Galaxy, Whirlpool Galaxy, Pinwheel Galaxy, Sombrero Galaxy and Comet Galaxy. An Elliptical Galaxy is that comprises of an ellitiod shape that is dim and almost emits an featureless image in space. An ellipsoid shape looks like the image of the cosmic microwave background. An example of an Elliptical Galaxy is Messier 87. A Barred Spiral Galaxy is like a Spiral Galaxy except that it has a bar-shaped center structure that is made with stars. Examples of barred shaped galaxies are The Milky Way Galaxy (our galaxy), Andromeda Galaxy, Virgo Stellar Stream and Triangulum Galaxy. 
Center of a Galaxy
Stars have a ton of mass and gravity. So thou can imagine the gravity that is contained in a Galaxy. It takes are good amount of mass to hold that together. So what is holding all the matter together? What is in the middle of a galaxy? Well what in The Universe has so much gravity that it collapse into itself, taking everything close to it with it? A Black Hole of course. Scientist believe that at the center of every Galaxy in The Universe, is a Black Hole. What else can hold all of this stuff together? Definitely isn't Earth. 
​Conclusion
Knowledge accumulate overtime through generation passing down of knowledge and books or other media. There are trillions of galaxies yes, will we name them all in our lifetime; probably not; does that mean our species never will? Not necessarily. Do not let the fact that you may not know all there is about The Universe make you quit your curiosity and yearning for knowledge. What good is it to know everything in The World? For if there is nothing new to learn, what is the point of exploration or curiosity. A major factor in human evolution overtime was curiosity and the thirst for knowing more. Without this key feature, what makes us human is lost. Do not yearn to know it all, but to learn as much as you want of what you want, and then pass that knowledge on to the next generation. This is a key survival instinct in humans that put us at the top in The World.