Most online services send data to distant data centres to be processed, which adds delay and strains networks. Edge computing instead does some of that work on nearby hardware, close to where the data is produced, so responses come back faster and less raw data has to travel.
This matters for anything that cannot wait for a round trip, such as live video analysis or industrial sensors. It does not replace central data centres; it complements them, handling the time-sensitive part locally while the heavier, less urgent work still happens centrally.