The entire line that is copied into the buffer, such as a record, is called $0.
Take the following command, for example:
$ cat people.txt
The output is will be as follows:
Bill Thomas 8000 08/9/1968 Fred Martin 6500 22/7/1982 Julie Moore 4500 25/2/1978 Marie Jones 6000 05/8/1972 Tom Walker 7000 14/1/1977 $ awk '{print $0}' people.txt
The output is as follows:
Bill Thomas 8000 08/9/1968 Fred Martin 6500 22/7/1982 Julie Moore 4500 25/2/1978 Marie Jones 6000 05/8/1972 Tom Walker 7000 14/1/1977
This has printed all the lines of the text file. Similar results can be seen with the following command:
$ awk '{print}' people.txt