The milky way is our home galaxy in the universe. It is fairly typical barred spiral with four major arms in its disk, at least one spur, and a newly discovered outer arm. The galactic centre, which is located about 26,000 lights per year from Earth, contains at least one super massive black hole (called Sagittarius A) and is crossed by a bar.
Up until 1920, most astronomers believed that all of the stars in the universe were contained inside the milky way. The oldest star in the galaxy is HD 140283, also known as the Methuselah star and it is at least 13.6 billion years old. The milky way is moving through space at a rate of 600 km per second and will collide with the Andromeda Galaxy, around 3.75 billion yrs.
The milky way is known as the barred spiral galaxy- it's shaped like a spiral with a straight bar across its centre. 2/3 of the galaxies in known universe are spirals, and about 2/3 of the spiral galaxies are barred, making the milky way a most common galaxy. Our solar system is perched in the centre of the Orion arm. The Orion arm was once considered a "spur," a minor protrusion compared to major arms like the Perseus arm and the Carina-Sagittarius Arm.
The milky way began as a series of dense regions in the early universe not long after the Big Bang. The first stars to form were in globular clusters that still exist. They are among the oldest stars formed in the milky way region. The milky way has grown by merging with other galaxies through time. It is currently holding some stars from a very small galaxy called the Sagittarius dwarf Spheroidal, as well as gobbling up material from the Magellanic clouds.