The Compromise of 1850 was meant to deal with new territory in the West without the country falling apart over the issue of slavery. To let California become a state without slavery, and to make Texas a little smaller, the North had to give the South something in return.
The main concessions were money (to Texas) and a much stronger law to deal with runaway slaves. The Compromise also organized the territories of Utah and New Mexico (deliberately sidestepping the slavery question), and banned the slave trade in D.C.
That's why it's called a compromise.
The new congressional policy of not dictating slavery in new territories was just a cop-out to force other people to make some of the controversial decisions.
It sure wasn't a compromise for the people most affected: slaves.
California decided it wanted to become a state but didn't want to have slaves. Congress had to figure out how to do that without breaking the country.
The Compromise of 1850 gets a bunch of things done at once. Starting with Clay's original list of resolutions, the text includes a series of statues that each addresses one of those resolutions. It's like you get the table of contents, then the chapters.
In order to keep everyone just happy enough to not declare war on each other, the Compromise includes five separate bills mostly about slavery, which together deal with a bunch of state governments, runaway slaves, and the slave trade in the nation's capital.