Choosing the right nail for your project is important. For example, you don't want to use a nail that's not galvanized on a fence or on roofing because when it's exposed to water it will rust and you definitely don't want that. Here are a few examples of nails and their applications.
1" Galvanized Roofing Nail
This zinc coated nail is used by roofers to hold shingles to your roof decking. The zinc coating prevents rust and as a result the nail will last a long time.
Double Headed Nail
This nail is used most commonly in temporary construction. For example, if you nail 2X4s together to create forms for concrete, this is the nail for you. Why? Because the double headed nail is pounded into the wood to hold it together. Then when you're ready to remove the forms from the concrete, the second head is sticking out so you can grab it with your hammer and pull it out of the wood very easily.
This nail is used for new construction, framing and remodeling jobs. It's coated so that it will penetrate into the wood easier and the coating has an added benefit of holding the nail into the wood better so it has less chance of backing out as the wood expands and contracts due to seasonal temperature changes.
This, as its name implies, is used in finishing work. It's most commonly used to nail in crown molding or base trim. Once the nail is hammered flush with the top of the surface, take a nail set and recess the nail head into the wood and cover with putty for a beautiful, strong finish.
6D Galvanized Fencing Nail
This nail is most commonly used when installing a fence. It is galvanized so it won't rust when exposed to the elements. And because it has a thin shank, it reduces the risk of splitting the wood when you're nailing.