"Is there internet?"
Translation:A bheil eadar-lìon ann?
The bi verb (whose forms tha and bheil are) needs some predicate – you cannot say just *tha Màiri, or *a bheil eadar-lìon? – that’s ungrammatical.
ann has several meanings: ‘in it, in him, there’.
English there can express general existence in sentences like are there humans on Earth? or there are two apples on the table, or is there Internet? meaning really does Internet exist?.
In Gaelic you use ann in a similar manner if you want to state existence of something and you don’t have any other predicate for the bi verb: tha Màiri ann ‘there is Màiri, Màiri exists’, a bheil eadar-lìon ann? ‘is there Internet? does Internet exist?’.
I’d say it’s a use of term for specific material object (spider web, fishing net) used as an abstract concept (lots of abstract interconnected nodes). And the word between is an abstract in itself. Nothing particularly modern about that usage (besides the fact that in this case it is naming a modern technology).
You’ll find the word for (spider, fishing) net used for computer networks, social networks, etc. used in many languages.