The holding period is the length of time you held an asset. It's usually measured from the day you buy the asset through the day you sell it.
Holding periods can be either long-term or short-term. If you hold an asset for more than one year, it’s a long-term holding period. If you hold an asset for a year or less, it's a short-term holding period. The holding period is important since it determines if the gain on your sale will be taxed at either:
A favorable long-term rate
The same rate as the rest of your income -- a short-term rate
The holding period of assets you receive as a gift might include the donor's holding period. The holding period of inherited assets is always long-term.