Marcos, short for "macros," refers to a set of instructions that automate tasks in software applications. They are commonly used in programs like Microsoft Excel to streamline repetitive processes, such as formatting data or generating reports. By recording a series of actions, users can execute them with a single command, saving time and reducing errors. In programming, macros can also refer to code snippets that expand into larger code blocks. This is often seen in languages like C and C++, where macros help simplify complex code and improve readability. Overall, macros enhance efficiency in both data management and software development.