Unix diff command

[jaba]

I cant for the life of me figure out what it means when I get;
437,462c449
I know that the C means change, but why are there two line numbers on the left side?

 

[sibanac]

I cant for the life of me figure out what it means when I get;
437,462c449
I know that the C means change, but why are there two line numbers on the left side?

replace the lines 437->462 from file 1 with the line 449 in file 2

 

[jaba]

beautiful, ta