A little addition to @Andy aka 's answer.
Your device uses I2C, or often called 2-wire serial communication.
In this communication protocol the master selects a slave by sending its address to the bus, and the specific slave identifies itself by this address.
Here is a picture of I2C's message frame.
As you can see there is a
Slave Address field which is 7 bit long. This is the address you set as it is described in the datasheet and in @Andy aka 's answer. The first (from MSB) 4 bit are fixed the last 3 could be set with (A0,A1,A2) pins.