What information can be gathered using the command 'uname -r' on Linux?

The command 'uname -r' in Linux is specifically designed to display kernel information. When executed, it provides the version of the kernel that the operating system is currently running. This information is crucial for system administrators and users who need to understand which kernel features are available, as well as for troubleshooting and system compatibility assessment.

In contrast, the other options pertain to different aspects of system information. For instance, while 'uname -r' can tell you about the kernel version, it does not provide data on installed applications, system memory usage, or CPU specifications. Each of those areas would require different commands to retrieve the relevant information. For example, installed applications can be found using package management tools specific to the Linux distribution, memory usage can be examined with commands like 'free' or 'top', and CPU specifications can be fetched using commands such as 'lscpu' or 'cat /proc/cpuinfo'.