[gentoo-user] wiki page(kernel/upgrade) command confusion: 'cat' and 'awk'

[russian sky]

the sentence is just as follows:

diff <(cat .config | sort) <(cat .config.old | sort) | awk '/^>.*(=|Linux)/ { 
$1=""; print }'

without inserting the 'cat' and '*'(the part of awk),It seems like, the result 
of the command is the same as before.


Does the existence of the aboving 'cat' and '*' (the part of awk) have some 
special meaning which make them necessary on the sentence?