Explain I2C communication protocol and its advantages.

I2C (Inter-Integrated Circuit) is a two-wire synchronous serial protocol supporting multiple masters and slaves on the same bus. Two signals: SDA (data) and SCL (clock), both open-drain with pull-up resistors. Features: 7-bit or 10-bit addressing for up to 128 or 1024 devices. Standard (100 kHz), Fast (400 kHz), Fast+ (1 MHz), High-speed (3.4 MHz) modes. Built-in acknowledgment mechanism. Multi-master support with arbitration. Only two wires needed regardless of device count. Frame: Start condition, address byte with R/W bit, ACK, data bytes with ACKs, stop condition. Advantages include simple wiring, addressing capability, and widely supported by sensors and peripherals.