What forces a query to run in parallel?

Hi

We noticed that on our 2 node 19c RAC database running on Exadata X7, a query was issued by one of the develpoper without a WHERE clause like select * from table_name

The query ended up using 96 parallel processes

We checked the table and the DOP of that table is set to default

Also there are some other queries that did have the WHERE clause end up using parallel processes although the table and the underlying indices all have DOP set to default

Here are the db level settings for parallelism

parallel_degree_limit        CPU

parallel_degree_policy     MANUAL

parallel_max_servers 345