Candle bulbs have a very distinctive, decorative shape. They are often used in decorative ceiling light fittings, and table lamps.
The fluorescent candle bulbs are now very small, and are only slightly larger than the smallest 'regular' incandescent candle bulb.
Candle bulbs with a standard bayonet (BC / B22) cap.
This is the 'normal' or 'large' bayonet cap that is commonly used in the UK with a diameter of 22mm. It can be found in all types of light fittings and fixtures.
Candle bulbs with an Edison screw (ES / E27) cap.
This is the 'large' size screw cap, the screw thread has a diameter of 27mm. It is quite common throughout Europe.
Candle bulbs with a small Edison screw (SES / E14) cap.
This is the 'small' screw cap, with a diameter of 14mm. The SES lamp cap is often used in table lights and bedside lights.
Candle bulbs with a small bayonet (SBC / B15) cap.
The small bayonet cap has a diameter of 15mm. It's quite uncommon, and is most often found in older ceiling lights.