Literally, Suppression and Concealment mean the same thing.
Suppression of fact is one’s not providing the informations regarding (at the time of appointment)- 1. Academics, 2. Criminal cases, if any, 3. Academic or professional degrees after appointment, 4. Marital Status (Working spouse), 5. Exact earning per annum and many more.
Providing false information is also liable to punishment/ impeachment.