Which command would you use to check overall memory usage statistics on a Linux system?

The command to check overall memory usage statistics on a Linux system is "free." This command provides a quick overview of the total, used, free, shared, buff/cache, and available memory on the system. It displays information about both physical RAM and swap memory usage, making it a straightforward tool for assessing memory status at a glance.

While other commands can also provide memory information, they do so in different ways or are more focused on performance monitoring rather than a simple snapshot of memory usage. For example, "vmstat" provides a range of system performance data, including memory but is more complex and includes various metrics beyond just memory. "top" and "htop" are interactive command-line tools that provide detailed real-time insights into system processes and their memory consumption, but they present a more verbose view and are not solely focused on overall memory statistics. Thus, "free" is the command that specifically targets memory usage in a clear and concise manner.