IVs are the "generalists" of vein access in medicine, whereas infusaports have a more specialized role, and are, in general, a bigger deal. One way of looking at this is
that IVs are the daily work horse of getting fluids and meds into a patient through the veins, and infusaports are the Mac Trucks for special jobs.
This gets a little technical. An infusaport, like an IV, offers entry into a vein. With the infusaport, medicine is given through a special needle. This needle is inserted through the chest skin into a surgically implanted dome or port connected to a catheter threaded into a large vein in the upper chest or neck. The infusaport is often preferred for giving chemotherapy or other intermittent treatments for a couple of reasons: One, the tube goes into a larger vein, which better tolerates some medicines than smaller veins. Two, the infusaport can remain in for months at a time, whereas the "shelf life" of an IV is only 3 to 7 days. So if someone needs frequent treatments, using an infusaport won’t cause as much wear and tear to the area, potential scarring and discomfort as numerous IVs.
The down-side is that getting the infusaport is a surgical procedure (outpatient, usually done with IV sedation and local anesthesia). With the surgical procedure, there is a small risk (less than 5%) of possible lung puncture or bleeding into the chest. Other risks include blood clot or infection. These risks can be minimized, respectively, with small amounts of blood thinner and with antibiotics.
The infusaport is easily kept functional when not in use with one injection of heparin (local blood thinner) a month. It’s visible as a small lump generally on the right side of the chest. You can swim, shower and generally live life as usual with an infusaport in place.
An IV is a thin, flexible catheter inserted, with the help of a needle, into a small (peripheral) vein, often in the arm or hand. The needle is removed, leaving the catheter and a hub or kind of valve into the vein. It’s capped-off and taped down when not being used. An IV can be quickly inserted by a nurse or paramedic. IVs are used for support during anesthesia, the quick administration of meds or fluids during medical emergencies, hydrating a dehydrated patient, brief regimens of antibiotics, and much more.