The threaded Edison Screw, or ES, is now more widely used than the bayonet cap. E in bulb names indicate this base - e.g. E27

The familiar bayonet cap features opposing prongs that slot into the holder. B is used to indicate a bayonet cap in bulb names. - e.g. B22 Light bulbs are available in multiple sizes and designs. A key differentiator is in the base - the part that clips or screws into the bulb holder.What is a GLS bulb? General Lighting Service bulbs feature the familiar, basic, pear-shaped design that has been in use for more than a century. They may have either bayonet or screw caps. CFL

This E14 bulb holder is available in either threaded or plain. Threaded is perfect for use with light shades, whereas plain looks fabulous shown off individually. These two bulb types are quite similar. Both provide warm, steady light in commercial and domestic settings and they are used for many of the same purposes. However, they feature different bases. The B22 has a push-and-twist bayonet cap while the E27 has a revolve-to-insert Edison screw. What is the Difference Between E14 and E27?