SHTC3 Temperature and humidity sensor
This sensor provides temperature and relative humidity readings on a single pin by using the I2C serial communications protocol.
I2C uses two wires as a data bus and several devices can connect to the same bus. The pins are labelled SDA (Serial data) and SCL (Serial clock). You just need to connect the power (3.3V) and GND as usual and then connect SDA on the sensor to the SDA pin on the microcontroller, and the same with SCL.
Use the instructions for your development environment to find the right library to use and to include it in your application.