An event, in computing terms, is an action or occurrence recognized and handled by a program and is important for system hardware and software. Events can be user-generated via mouse clicks, keystrokes, or touch screen, or system-generated like errors, restarts, or application triggers.
An event log is a resource that stores information about the occurrences or events in a given system, network, or application. Information like access, delete, addition, modification, or shut down is stored so that admins can retrieve them to troubleshoot issues or manage the IT environment at any time. Event logs are the primary sources for troubleshooting, as they provide valuable information, both security and performance-wise.
A log is a record of events thoroughly documented about everything that happened over a period. An event is a particular occurrence or happening, and is a single record retrieved from indexing or searching.