Concurrency is dealing with multiple things at once (does not need to be done at the same time) with some time schedule while parallelism is doing the things at once at same time
Different parts of the program are executed independently in concurrency
Different parts of the program are executed at the same time in parallelism
Concurrency models are OS threads, Green threads, Async IO
Parallelism models are OS threads, Green threads
Generally concurrency is good for IO bound operations while parallelism is good for CPU bound operations
IO bound are network connections, disk operations, api calls etc
CPU bound are image processing, machine learning etc
