A 118-degree drill bit is better suited for softer materials like wood and plastic. It has a more aggressive shape and a smaller chisel, and the tip is pointed. While it will puncture steel, the 118-degree drill bit will dull quicker.
A 135-degree drill bit punctures harder materials like metal and masonry. It has a flatter shape with a shorter chisel but has more pitch. These bits are better suited to drilling repeated holes.