Glossary
Info (information)
In one line: Everything you know about the enemy: where they are, how many, with what guns, what they used.
What it means
In VALORANT "info" is anything that tells you something about the enemy: footsteps you heard, a red marker on the minimap, a trap going off, a teammate dying in a certain spot, an ability used, time passing with no contact.
The game is largely a race to have more information and use it better. A team that knows where the enemies are wins far more rounds, even with worse aim. That is why you share information, use abilities that gather it and avoid giving it away (running loudly, showing yourself for no reason).
An example
You hear two sets of footsteps in A main and see a drone in mid. You say "two A main, drone mid". Three pieces of information in five words: the team knows A is under threat and the attack is scouting mid.