Long Term Capital Gains Tax is the tax that is payable on the gains generated from the sale of an asset or investment which has held for a time period classified as long-term. The time period which gets classified as long-term depends on the class of the asset.

For example, in case of debt mutual funds and jewelry, holding period of more than 3 years is taken as long-term.
However, in case of equity shares, bonds, government securities, UTIs, equity mutual funds, zero coupon bonds, holding period of more than 12 months is taken as long-term.