A typical full-time business (or home!) connection to the Internet
involves:
Choosing an ISP who offers permanent Internet access at a
reasonable pricing plan (with "livable" download limits...) in the
geographical area where the business is located -- ie, one which
has a local POP.
Choosing the basic-carriage technology (or "leased-line"
technology) which they will use to facilitate the data connection
to the ISP. In Australia, this is separated from the ISP charge
because, for traditional communications services like the PSTN,
Telstra has an effective monopoly, since it owns virtually all of
the local loops. One of the conditions of Telstra's
semi-privatisation was that "value-added" competitors would have
equal access to the basic network. This restriction is removed in
situations where the Telstra monopoly doesn't apply. A good example
is Cable TV-based access technologies.
Managing several other issues, such as the purchase of a
suitable modem/router (which could be a dedicated box, or an
ordinary computer system running appropriate software), registering
and delegating a domain name, assigning IP addresses, setting up
necessary servers and lots more.