dphys-swapfile:tldr:4c58e

The command "dphys-swapfile swapon" is used to enable the swap file in the Raspbian operating system.

In Linux, a swap file or swap space is a designated area on the hard drive that is used as virtual memory when the system's physical memory (RAM) is full. When RAM gets filled up, the operating system moves the least used or idle parts of memory to the swap space to free up RAM for more active processes.

The "dphys-swapfile swapon" command, specifically in Raspbian (the Debian-based operating system for Raspberry Pi), is used to activate the swap file that has been configured on the system. It informs the operating system to start using the swap space for virtual memory management.

By enabling the swap file, you effectively increase the available memory for your Raspberry Pi. However, it is important to note that using swap file can result in decreased performance compared to running entirely on physical memory, as accessing data from the disk is slower than accessing it from RAM.

To summarize, the "dphys-swapfile swapon" command enables the configured swap file in Raspbian, effectively expanding the available memory by using a designated area on the hard drive for virtual memory management.