In the below awk syntax, what does the value '1' signify?

awk '{....}1' file

some eg:

awk '{gsub(/[^[:cntrl:]]/,"")}1'
awk 'BEGIN{ORS=""}1'
awk '{ORS=(!(NR%5)?"":"\n")}1'

awk evaluates the 1 as true and the prints the entire line by default, including a newline.

echo 'foo' | awk '/foo/{print}1'

But, what does 1 serve here or what is the role/purpose of 1?
Anyway, the default action of awk is to print the record right, even if the 'print' statement is missing?

Don't take everything for granted.

$ echo 'foo' | awk '/foo/'            #default action
foo

$ echo 'foo' | awk '/foo/{print}'     #defined action
foo
$ echo 'foo' | awk '/foo/{$1="bar"}'  #defined action

$ echo 'foo' | awk '/foo/{print}1'    #defined action and default action
foo
foo

$ echo 'foo' | awk '/foo/{$1="bar"}1'
bar

Thanks danmero, I got the essence !! hat's off