Isro
In short
The Indian Space Research Organisation is the national space agency of India, responsible for all space-based operations and exploration for the country.
In plain words
It is a government group that builds and launches satellites into space. They also study the moon, planets, and help with communication and navigation systems.
A simple example
ISRO launched the Chandrayaan missions to explore the surface of the Moon. They also run the IRNSS system to help with satellite navigation.
Why it matters
It allows India to have its own technology for weather monitoring, telecommunications, and disaster management. It also helps the country compete in the global space race.
Easy to mix up
Do not confuse it with NASA, which is the space agency for the United States.