Domains vs data types

Hello,

I am using PostgreSQL 17.6.
I would like to learn if there is any benefit of using domains over data
types for table column definitions in terms of performance gain/loss.

For example I might have table defined as below
create table test (
a integer,
b integer,
c integer,
d varchar(5)
);

I might also have ame table defined as below

create domain aint integer;
create domain s5 varchar(5);

create table test_domain (
a aint,
b aint,
c aint,
d s5
);

Does the second table have any technical advantage/disadvantage over plain
data type definition?
Less metadata in memory? High metadata in memory? Less/increased disk space?

Thanks & Regards,
Ertan