Masters such as a processor need to access slaves such as peripherals and memory. Masters access slaves by reading and writing to specific addresses over an interface such as AXI. IP integrator can create address assignments whereby slaves are visible to masters at specific address ranges. These address assignments are used to configure the masters and the interconnect IP such as the SmartConnect so they correctly route transactions based on the addresses.
Addressing can quickly become complex with nuanced rules, but the basics are straight forward.