A standard air conditioning system is comprised of one indoor unit and one outdoor unit. This is called a split system.

A multi-split system is comprised of multiple indoor units (up to 5), connected to one outdoor unit. 

The main advantage of a multi-split system is that you only need space for one outdoor unit. This makes it great for installations that are limited for outdoor space. 

Indoor units can be mix and matched. Wall mounted, floor mounted, ducted and more. All connected to one outdoor unit. 

Prices for these systems are more bespoke, and require a site visit to ensure accuracy.