Wire nails are specially designed fasteners that have extra grip due to the gripper marks created during the manufacturing process.
They are made by feeding wire coils in a machine that cuts grooves and ridges into the nail shank. Although they typically have a broad head, the size varies according to its intended application.
Wire nails are an incredibly economical and versatile fastener in many, if not all building or fixing projects including woodwork. However, take note that due to their grooved and ridged design, they can be useful but also detrimental depending on your project.
For example, they are prone to splitting the wood that they are being hammered into. Thus, they are more suitable for heavy duty woodwork that uses materials which can take advantage of its extra grip without breaking.