User defined table is not present in postgresql.

Hi,
I am new to postgres and presently migrating from sql server to postgres and facing some problems. Kindly help me with this.
We have user defined table in sql server, I am unable to find the same in postgres. Postgres have the concept of Types but
The problem is I cannot set the default value of a column in Types available in postgres. I will be highly obliged if you solve me through
This.

Thanks and regards,
Sayan Majumder.
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