The Seeeduino Nano is a compact board similar to the Seeeduino V4.2 / Arduino Uno, and it is fully compatible with Arduino Nano on pinout and sizes. Seeeduino Nano is built around Atmega328P, the popular 8-bit AVR microcontroller.
Seeeduino Nano has also the following improvements compared to the Arduino Nano. The Mini-USB into Type-C, which is symmetrical and reversible and one Grove I2C connector. Is one on-board Grove connector not be enough, then the Grove shield for Arduino/Seeeduino Nano can be used.
More information is available on the website of Seeed Studioand wiki.