Do short-term losses from a stock sale offset short-term capital gains for tax purposes?

A short-term loss/gain is either the loss, or gain, of capital upon the transaction of an asset that you held onto for a year or less. A long-term loss/gain is the same thing but you had the asset for over a year, before disposing/selling it. On a taxes standpoint, when you have a short-term loss, it will offset the gains that are of the same type, first, so short-term gains would be offset. A long-term loss would act in the same way: offsetting the long-term gain, first. After the appropriate gain has been offset, if the loss still persists, then long-term gains can start to be offset by the losses. It is best that your losses don't go over your gains.