Backup & Restoration – Postgres supports two types of backups – logical and physical.
Logical backup copies table by table as if any client performing series of SELECT statements. It is a reliable and simple method that works across major versions. However it takes more time and puts additional cpu and memory strain on the cluster (it requires a transaction to persist over duration of the backup). It only copies the data that exists at the time when backup starts – thus the backed up data can be already outdated one it completes.
Physical backup is less invasive – it copies data from files (PGDATA/base and WALs) and allows Point in time recovery. However it is more complex to perform and recover. It works only within major versions. It can cause a spike I/O bandwidth.