WASHINGTON — Just weeks before leaving office, President Obama on Monday issued 78 pardons and commuted the sentences of 153 prisoners, extending his acts of clemency to a total of 1,324 individuals, one of the larger uses of the presidential power to show mercy in modern presidential history.

The Recipients

Of the 231 people who received a pardon or a reduced sentence from Mr. Obama, virtually all had been serving sentences under tough antidrug laws, including those convicted of low-level, nonviolent crimes like possession of cocaine.

Those who received pardons had completed their sentences and are, in the words of Neil Eggleston, the White House counsel, now leading “a productive and law-abiding post-conviction life, including by contributing to the community in a meaningful way.” The pardons wipe away any legal liabilities from a conviction.

Commutations are different. They typically shorten the sentences of people in prison, often by many years, but do not eliminate a conviction or restore rights lost, such as the right to vote. In many cases, the people selected to have their sentences commuted have participated in drug treatment, or educational or vocational technology courses while in prison.