What is the difference between "Web Services" and "web services"?

Answer 1

A web service is any service delivered over http that is intended to be read by a program rather than a human.

Answer 2

I've seen the distinction used where "Web Services" is used to indicate SOAP-based services and "web services" to indicate either non-SOAP services and/or any type of web-based service irrespective of application protocol. However, I don't think there are any hard-and-fast rules, and you certainly can't make any assumptions based on capitalization.

I'd also be wary about labeling non-SOAP as 'startup level' or 'informally defined' as there are many very large companies using this type of service (Google, Amazon, Facebook, Flickr, ...) and the services are neither startup level nor informally defined. And you'll probably find they're more 'enterprise ready', mature, and dependable than most so-called "enterprise" web services (irrespective of capitalization). Most of these things have more to do with the capabilities of the engineers implementing them than the actual choice of application protocol or technology.

Answer 3

I don't think that there is a difference between "Web Services" and "web services". Any occurrence of one or the other is just the habit or convention of the particular author.