What is mb meaning in text?

MB stands for "megabyte" which is a unit of digital information that typically refers to the size of a file or the amount of storage space available on a device. It is commonly used in text messaging, email, and other forms of digital communication to indicate the size of a file that is being sent or received. For example, if someone sends a photo that is 5 MB in size, it means that the file is five megabytes in size.