Drives nails (up to 4-3/4 in. long) easily in tight spaces, without the strain and restrictions of swinging a hammer. Add a few drops of oil to the airline connection before use. Add a few drops more after each hour of continual use.
There are a lot of YouTube videos on how to use a palm nailer, about different brands, etc. None are GREAT; try this one (starts mid-way through):
https://youtu.be/jGBNccuLtBE?t=116