The expressions Assets and Blocks of Assets w.e.f. 1-4-1999 shall mean a group of assets falling within a class of assets comprising:–
a. Tangible Assets being buildings, machinery, plant or furniture;
b. Intangible Assets being knowhow, patents, copyrights, trademarks, licences, franchises or any other business or commercial rights of similar nature; in respect of which same percentage of depreciations is prescribed.
Refer sec 32 of IT ACT 1961