initrd or not

[bob parker <bob_parker@dodo.com.au>]

hi Debian-users,

I installed Woody and got the default 2.2.20-idepci kernel.
Later I updated that to 2.4.18-k7 kernel using apt-get.
Then just for fun I compiled a 2.4.19 from tarball making the
.config from what came  with the 2.4.18 kernel without any 
changes. I did the make modules, make modules_install etc.

I had to mkinitrd in order to get this new kernel to boot.

What are the pros and cons of initrd?
And also, if not use it, how to configure the kernel to
do without it?

Regards
Bob Parker