NTP.conf pool vs server

[ray <ray@aarden.us>]

I would like to know the correct syntax for entering a server entry for stretch.

All the documentation I find says to list the ntp servers in the file as:
server 0.XX.pool.ntp.org 
server 1.XX.pool.ntp.org 

An example source from 2017 is https://wiki.debian.org/DateTime

When I open /etc/ntp.conf on my new stretch installation, I find this format:
pool 0.debian.pool.ntp.org iburst
pool 1.debian.pool.ntp.org iburst

The latest Debian doc says to start the line with 'server'.
The latest Debian implementation starts the line with 'pool'.

Are these interchangeable?

Additionally, there is a parameter 'iburst' which I did not find in the Debian docs but found at http://doc.ntp.org/4.1.1/confopt.htm


Thanks,
Ray