What does BLS stand for?

Excuse me, I'm curious about a term I've encountered in the cryptocurrency and finance world. Could you please clarify for me what BLS stands for? I've heard it mentioned in relation to blockchain technology and digital currencies, but I'm not entirely sure of its full meaning or significance. Your expertise in this field would be greatly appreciated in providing a concise yet comprehensive explanation of this acronym. Thank you in advance for your time and assistance.