LARTC - Jun 2002 - Question about qdisc and class

I have a question about the difference between a qdisc and a class and a
classid and a flowid, I am reading the HOWTO but I am a little confused
about this.

I see lines like this:
tc filter add dev eth1 parent 1:0 protocol ip prio 100 match ip src \
  1.2.0.0 classid 1:1

Then I see one like this
tc filter add dev eth1 protocol ip parent 1:0 prio 5 u32 ht 2:7b: \
        match ip src 1.2.0.123 flowid 1:1

I do notice there is a difference I''m just not sure why you use classid
in one and flowid in the other.


I also see stuff like this

tc qdisc add dev eth0 root handle 1: htb default 30
tc class add dev eth0 parent 1: classid 1:1 htb rate 5mbit burst 15k

and I''m not sure why the command changed from qdisc to class.

If there is more documentation some where could you point me to it or
let me know what the differences are here.

Thank you all for your time.

Zoop