Merge multiple text files into another file

One way to merge multiple text files into a new text file is to use the cat command.
cat file1.csv file2.csv > file3.csv
This command merges file1.csv and file2.csv into a new file called file3.csv

we can also append to an existing file instead of creating a new one
cat file1.csv file2.csv >> file3.csv
This merges the contents of file1.csv and file2.csv and adds it to the contents of file3.csv