Answer:
The GLS (General Lighting Service) is a traditional type of light bulb that has been in use since the early twentieth century.
It has the classic, pear-like light bulb shape and its versatility means it is still one of the most popular types of light bulb available today.
GLS light bulbs are commonly fitted with either a B22d bayonet cap (sometimes abbreviated to BC) or an E27 Edison screw (ES) base. The B22d cap is the ‘push and twist’ type of fitting that is used on the majority of lamps in the UK, while the E27 is the screw-in type that is more common in Europe and the US
Explanation:
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