What does ICO stand for?

As a keen observer of the financial and cryptocurrency landscapes, I often come across the acronym "ICO" in various discussions and news articles. Could you please elaborate on what exactly does "ICO" stand for? I've heard it being referenced in relation to fundraising and new cryptocurrency projects, but I'm not entirely sure of its full meaning and significance. Your explanation would greatly help me in understanding the concept and its implications in the world of digital currencies and blockchain technology. Thank you in advance for your clarification.