An ICO, or Initial Coin Offering, is a fundraising method used by startups to raise capital for new cryptocurrency projects. In an ICO, a company sells a portion of its digital tokens to investors in exchange for established cryptocurrencies like Bitcoin or Ethereum. This process allows investors to support innovative projects while potentially earning returns if the project succeeds. ICOs gained popularity in the early 2010s, offering a quicker and less regulated alternative to traditional funding methods like venture capital. However, they also carry risks, as many ICOs lack oversight, leading to potential scams or project failures. Investors should conduct thorough research before participating.