mkswap:tldr:7b68d

This command is used to create a swap area on Linux systems. The parts of the command can be explained as follows:

• sudo is a command that allows a user with administrative privileges (usually the root user) to execute a command.
• mkswap is a command that creates a swap area, which is a portion of the hard drive designated for virtual memory.
• -L is an option that allows you to assign a label to the swap area. ${swap1} represents the label for the swap area, and it is a placeholder that must be replaced with an actual name or label.
• ${filename} represents the file or device that will be used for the swap area. It is also a placeholder that must be replaced with an actual file or device.

So, when you execute this command with the appropriate values for ${swap1} and ${filename}, it will create a swap area labeled ${swap1} using the specified file or device ${filename}.