paste:tldr:dfcaa

This command is using the paste command in the Unix/Linux terminal. The paste command is used to merge lines from multiple files side by side or sequentially.

In this specific command:

• -d '\n' is an option provided to specify the delimiter used to separate the merged lines. Here, the delimiter is set as a newline character (\n), which means that each line from file1 and file2 will be separated by a new line in the output.
• ${file1} and ${file2} are placeholders for the actual file names or paths. It is expected that these placeholders are replaced with the names or paths of the files you want to merge.

So, this command will merge the lines from file1 and file2 together, with each line from both files separated by a new line, composing the final output.