I own a Garmin GPS (a somewhat older Nuvi-1450 w/ 5-inch touch-screen), which came with lifetime map-updates. I prefer such an external unit (rather than the built-in 'head' unit choice from a car dealer), so that once I have the various locations entered into it, I can then take whichever of two vehicles on vacation, and just plug my external GPS unit into the cigarette lighter, suction-cup it onto the inside windshield, and I'm good to go.
So, over the last few years, I've entered maybe 40 or 50 different address-destinations. When I stayed on vacation for two months in Florida, I entered maybe another 10 or so for that city's area. And, sure enough, when I decided to return the next year and stay in the same city, I was already ALL SET ! I could drive to various grocery stores, etc, etc, because I still had that location data in my GPS unit from the prior year. Also, when I saved all the Florida locations, I gave them 'prefixed' names, so I could easily recognize them in my 'favorites' list. I had prefixed them all with the leading "FL-" string, so then had names like "FL-Walmart", and "FL-BestBuy", and "FL-Publics", etc.
I mention all this, because I now want to talk about importing and exporting such location data. So, what if I now decide to buy a NEW model of a Garmin. Rather than having to re-enter all my locations again into the new unit, wouldn't it be neat if there was some way to just 'export' them all (e.g. onto my PC), and then 'import' them into the new unit? Of course you can, if you are just a bit techically inclined and are willing to spend the time learning how to do it.
The most recommended piece of (free) software for such exporting and/or importing is named GPSBabel
But, wait, there's more. Do you know about GPS 'routes'? (A 'route' is simply two or more location points strung together into a named route.) So, if you've learned to create such routes, you can also export and import them, too. One caveat, tho...routes are somewhat of an advanced concept and are somewhat tedious to enter into a GPS. Here's a generic (non-model specific) guide to understanding and using GPS 'routes'
And,did you know that, if say you're a hiker or kayaker or whatever, and want to enter a wilderness location
into your GPS (so you could then email that location to someone else who will
be meeting you there), you could first locate that given place on say, Google Maps or MapQuest, then deternine
its LATITUDE/LONGITUDE co-ordinates, and then take those co-ordinates and go enter them into your GPS
to navigate your vehicle to that exact spot? And, as an added bonus, you could now also email
that LAT/LONG location to a friend (assuming his/her GPS allows LAT/LONG data entry).
YEP, my Garmin Nuvi-1450 is almost 7 years-old, yet it even supports the ability to enter a location
as a LAT/LONG so I'm betting that your GPS probably does, too.
A key finding after doing more research (in early 2017) on the recommended GPS units convinces me that the most important attribute of any new unit is that it be using Google-Maps map-data (and probably that it uses the std/most-familiar Google-Maps UI, too???).
(Google's NEWEST offering is an app'called "Android-Auto", which can be installed on newer phones,
as well as being available as built-in/car-dealer installed in the very newest of vehicles.
But...a HEADS-UP...most all reports I've read from owners and reviewers say that Android-Auto is
still NOT ready-for-prime-time...that it contains TOO many new features (such exotic stuff as being
able to voice-command the system to play different music, dictate your shopping list into the phone,
all while the phone's active app is still Android-Auto). That's a LOT to bite-off in a single new app
so I'm not surprised that it is still beta-quality.
Bottom line: "try before you buy"!
So, I think this means that a better solution, in order to achieve my Google-data requirement, is to use somewhat-older Google Android apps (and thus finally replace my flip-phone with a modern Android phone. My research also recommends getting a vertical windshield-suctioncup mount to clip the phone into, anytime you want to navigate anywhere in your vehicle. (And, of course, you can still make phone calls, without having to remove your phone from the windshield mount.)
Oh, one last app that should be considered is a series of apps from a company called Waze, that Google acquired a few years ago. (Thanks, Ken, for reminding me about Waze!).