The /etc/group is a plain text file still used in Debian 13 (Trixie) as it core component¹ of user and group management. There is one entry per line, and each line has the following format (all fields are separated by a colon (:).

Group Name	Password	Group ID	Members
root	x	0
daemon	x	1
bin	x	2
sys	x	3
adm	x	4
tty	x	5
disk	x	6
lp	x	7
mail	x	8
news	x	9
uucp	x	10
man	x	12
proxy	x	13
kmem	x	15
dialout	x	20
fax	x	21
voice	x	22
cdrom	x	24	bhdicaire
floppy	x	25	bhdicaire
tape	x	26
sudo	x	27
audio	x	29	bhdicaire
dip	x	30	bhdicaire
www-data	x	33
backup	x	34
operator	x	37
list	x	38
irc	x	39
src	x	40
shadow	x	42
utmp	x	43
video	x	44	bhdicaire
sasl	x	45
plugdev	x	46	bhdicaire
staff	x	50
games	x	60
users	x	100	bhdicaire,badicaire
nogroup	x	65534
systemd-journal	x	999
systemd-network	x	998
crontab	x	997
input	x	996
sgx	x	995
clock	x	994
kvm	x	993
render	x	992
netdev	x	101	bhdicaire
scanner	x	102	saned,bhdicaire
tss	x	103
systemd-timesync	x	991
messagebus	x	990
_ssh	x	104
ssl-cert	x	105
bluetooth	x	106	bhdicaire
avahi	x	107
lpadmin	x	108	bhdicaire
pipewire	x	109
fwupd-refresh	x	988
geoclue	x	110
gnome-remote-desktop	x	987
saned	x	111
polkitd	x	986
rtkit	x	112
colord	x	113
Debian-gdm	x	114
bhdicaire	x	1000

Cheat Sheet

Find Out the Groups a User Is In: groups {username}

Sample outputs:

Print user / group Identity id -g vivek

To create a new group named sales, run: sudo groupadd sales sudo groupadd –gid 3000 blogusers

ceate a new system group named sysftp? sudo groupadd –system sysftp