ÔaccessesÕ, meaning that the name provides a causal pathway to the thing, mediated by the Internet.
¥Understand ÔaccessÕ as inclusively as possible, so this includes uses of an IRI to access a website, an http endpoint, a ÔrepresentationÕ (in the REST sense) of a resource, a server, a file, an html page, a mailbox, a webcam, É anything at all that can receive, send or be directly influenced by, or indeed itself be, any piece of information that can be transferred by a transfer protocol, either now or in the forseeable future.
¥Cast this net as broadly as you like, the accessible things will always be an extremely small subset of the set of all things that can be referred to.  Moreover, although one can of course refer to accessible things, most acts of reference will be to things not in this class, because most of the worldÕs business is concerned with other things than the architecture of the internet. (Example: the weather in Oaxaca.)

¥Historical note: the word ÔresourceÕ meant Ôaccessible thingÕ in the early writings of Engelbart and others. This corresponds fairly accurately to the English meaning of ÔresourceÕ, unlike subsequent W3C usage. The newer notion of Ôinformation resourceÕ might be similar to Ôaccessible thingÕ, but it may be narrower.