Earthly introduces "Earthly Functions," a feature designed to enhance modularity and reusability in software builds, by allowing developers to create reusable sets of instructions similar to functions in programming languages. These functions, defined in Earthfiles, operate like build targets but with the added benefit of inheriting the build context and environment, enabling more efficient and less redundant code. Earthly Functions can be invoked using the DO command and can be imported from other Earthfiles within the same or different repositories, exemplified by the use of Earthly lib for common operations. This feature is accessible through the open-source Earthly platform, with Earthly Cloud offering additional resources like 6,000 free build minutes per month. Gavin Johnson, Earthly's director of product and marketing, encourages users to explore these functions and provides insights into their benefits for software development lifecycle (SDLC) monitoring.