The prefix "mega-" is derived from the Greek word "megas," meaning large or great. It is commonly used in various fields, such as science and technology, to denote something that is significantly larger than the standard size. For example, a megabyte is a unit of digital information that equals one million bytes, indicating a large amount of data. In everyday language, "mega-" can also describe something impressive or extraordinary. For instance, a megastore refers to a large retail establishment that offers a wide variety of products. This prefix helps convey the idea of scale and significance in both technical and casual contexts.