I2C is the two-wire serial communication protocol. The I2C protocol stands for Inter-Integrated Circuits. The protocol uses two pins for sending and receiving clock data as well as serial data: a serial clock (SCL) pin and a serial data (SDA) pin.

• SCL-It stands for Serial Clock. It is used for sending the clock data between the devices. It is also used for synchronization purposes; this pin is provided by the master device.
• SDA-It stands for Serial Data. This pin is operated by both the slave and master device. The purpose of this pin is to send and receive the data. That’s why it is also called a data line, while SCL is known as a clock lines