What is the difference between adduser and useradd?

useradd is native binary compiled with the system. But, adduser is a perl script which uses useradd binary in back-end.

adduser is more user friendly and interactive than its back-end useradd. There's no difference in features provided.

Source: What's the difference between “adduser” and “useradd”?

Always use adduser (and deluser when deleting users) when you're creating new users from the command line. (If you're writing a script, especially if you aim for portability, you might want to use the lowlevel utilities instead – and adduser/deluser might not be available on all distros, e.g. on SuSE.)

The useradd, userdel and usermod commands are lowlevel utilities which are there for historical reasons, while adduser/deluser Do The Right Thing™. (I remember which to use by thinking that user* comes after adduser/deluser in the alphabet, and therefore is "worse".)

According to the respective manpages (on Ubuntu 12.04 Precise Pangolin, i.e. a Debian derivative system).

Manpage for adduser says:

(Emphasis added.)

adduser and addgroup add users and groups to the system according to command line options and configuration information in /etc/adduser.conf. They are friendlier front ends to the low level tools like useradd, groupadd and usermod programs, by default choosing Debian policy conformant UID and GID values, creating a home directory with skeletal configuration, running a custom script, and other features. adduser and addgroup can be run in one of five modes:

Manpage for useradd says:

useradd is a low level utility for adding users. On Debian, administrators should usually use adduser(8) instead.

See also: What's the difference between “adduser” and “useradd”? (on SuperUser)

adduser: add user with full profile and info (pass, quota, permission, etc.)

useradd: add user with his name only (if you want to add a temp user with only a name,other info not required)