Karakura Town: Birthplace of Ichigo and most of his friends.
An area in western Tokyo, where Ichigo and his friends live,
go to school and it is also where they fight against most of the Hollows.

Soul Society: Soul Society consists of an enormous city, which
is called Seiretei (the court of pure souls), which is where the
Death Gods reside. Outside of that lies Rukongai (Town of
Wandering Spirits). This is where all the non-Death Gods live.
This part of the city is divided into 80 big districts, where
district number 1 being calm and civilized, and number 80 is
filled with criminals and has lousy living conditions.

Hueco Mundo: Hueco Mundo is a big desert looking world, that lies between the
human world and Soul Society. Hueco Mundo is spanish, literally meaning
“hollow world”. Hollows can drag human souls into Hueco
Mundo to “eat them”. And unlike Soul Society, where traveling requires
specialized gates, the Hollows can travel between the Human world and
Hueco Mundo at will.

Hell: This is the place where humans go who were too corrupted during their human
lives. After a Hollow is slain by a Death God, a human soul that is too corrupted to enter
Soul Society, the gates of hell open and a
gigantic spiritual being drags the wicked soul down to Hell.