Difference between a subsystem and a component

Before UML 2.0 I could perfectly see a <<subsystem>> as a design-time <<component>>, which would finally become a <<component>>. The UML 1.4 defines component as "A modular, deployable, and replaceable part of a system that encapsulates implementation and exposes a set of interfaces. A component is typically specified by one or more classifiers (e.g., implementation classes) that reside on it, and may be implemented by one or more artifacts (e.g., binary, executable, or script files)."

After the aforementioned "fuzziness" was introduced to the UML (in UML 2.0), I am more inclined to use <<subsystem>> as a larger <<component>>, and see both of them as replaceable and reusable constituents of a system.

I have to agree with Preet, but practically, a subsystem is larger than a component. I use components for libraries (either bought, pillaged, or built) and subsystems for a part of the whole system that performs a given integrated function. For example, in a blood processing device, the centrifuge driver and control would be a component. The integrated blood suction regulation (which includes safety mechanisms, motor control, user control, and communications) would be a subsystem.