What is the difference between Reservoir and paratenic hosts?
Reservoir host: The host of an infection in which the infectious agent multiplies and/or develops and on which the agent is dependent for survival in nature; essential host for maintenance of the infection when active transmission is not occurring.
Paratenic host: A host in which a parasite survives without undergoing any additional development (a transport host only)
Source: Diagnostic medical parasitology, pg 1161

and

Any animal that harbors an infection that can be transmitted to humans is called a reservoir host, even if the animal is a normal host of the parasite. Source: Pg no:4

So, we can conclude that paratenic host is different from reservoir host due to following differences:

Paratenic host don't harbour infective stages , if they harbour them, then they would be called as reservoir host but not paratenic host( see second definition)

No development takes place in paratenic hosts, whereas in reservoir host development and multiplication takes place( see 1st definition).




Is a reservoir host a biological vector then?

I too asked the same question, its answer is here.