Both technologies have good capabilities in terms of performance. But PostgreSQL has some benefits due to its open-source availability, which is much lighter and less expensive.
The following companies use PostgreSQL:- Uber, Netflix, Reddit, Spotify, Instagram, etc.
By learning PostgreSQL, you can build an excellent career in the tech field. It is a popular database among developers and many other IT professionals. Also, you can earn many lucrative perks with these skills.
PostgreSQL uses a protocol based on messages to connect between the clients and servers (frontends and backends). Also, this protocol is applied through TCP/IP.
However, PostgreSQL is only a partial or not a replacement for Oracle's database. But a Developer or Database Admin familiar with Oracle DB will locate PostgreSQL to be related.