A Primer on Wi-Fi
Do you really know what wi-fi is? What does "wi-fi" even stand for?
If you're over about the age of 35 or so (as of this writing, 2015), then you probably had a home stereo, or "Hi-Fi" system and you know what "Hi-Fi" means. For the rest of y'all raised on iPods and ear-buds, "Hi-Fi" means High Fidelity -- a high-quality stereo system with really good speakers that accurately reproduces recorded music.
Someone decided that "wi-fi" would be a good name for the local, short-range wireless networks that we all use to get to the internet in our homes. In this context, "wi-fi" stands for Wireless Fidelity, which in itself means absolutely nothing. These terms don't even belong in the same sentence. I just groaned when I first heard the term "wi-fi" because I knew it would catch on. And so it has.
Although "wi-fi" itself stands for a meaningless term, it does represent something very specific. When we say "wi-fi", we are referring to a specific type of wireless protocol. This protocol is used to connect laptops, smart phones, tablets, and printers to a local, short-range (within a single building or residence), access-point that is connected to a hard-wired modem for accessing the internet.
This distinction is important. Smartphones all have two ways to access the internet -- cellular and wi-fi. Both ways are wireless, obviously, but only one is called "wi-fi". As it turns out, understanding that difference is pretty important.
Save on Your Phone's Data Plan
I've visited many clients who did not realize their smartphones could access their home wi-fi networks. Sure, their laptops were connected to the wi-fi, but not their phones. Since the phone could access the internet (via cellular) then it didn't occur to these clients that anything else needed to be done, e.g. connecting to the home's wi-fi network. After all, the phone can get online, so what else is there to do, right?
Why is that a big deal? Because using cellular on your phone chips away at your monthly data allotment. If you enjoy data-intensive activities on your phone (watching videos, especially) but even sharing photos or streaming music for several hours a day, then you can easily hit your data allotment for the month and incur additional fees from your cellular carrier (Verizon, AT&T, etc.)
But if your phone is connected to a wi-fi network, then all data is routed through the wi-fi instead. That means you aren't using your cellular data. Instead, data flows through the wi-fi which connects to your home internet service, which even if it does have caps, it's far higher than your phone's data plan. If you regularly exceed your cellular data plan allotment, there's a good chance you aren't connected to your home wi-fi.
If you don't have a wi-fi at home, but you do have internet, then a wi-fi device can be easily added and there's no additional monthly expense. Just a one-time cost for the device itself. You'll save that much in as little as one month by not going over your cellular data plan.
Local and Short Range
Local and short range to be sure! A single wi-fi router can usually cover a modest home if the device is centrally located, but there are many factors that can affect that. Normal household obstacles like walls, appliances, furniture, etc. dramatically affect indoor wi-fi performance. Radio signals are attenuated with every thing they pass through.
If your home is larger (over 2,500 sq/ft or so), has two floors, or lots of interior walls and such, or if your wi-fi router is positioned near an outside wall or corner, then you may wall have poor signal quality on the opposite end of your home. If you are using wi-fi for television streaming (e.g. Netflix) then distance plays a huge role in performance. The farther and weaker the signal, the slower the connection, which can mean buffering and dropouts.
There are various technologies that can extend reliable wi-fi coverage to all corners of your home. The gold standard is to have wireless access points at key locations around your home and have them all hard-wired to a central switch. But most homes don't have appropriate wiring installed and pulling such wire in a completed home can be difficult.
There are devices that transmit networking signals over regular electrical wiring in a home. In my observation, these devices work well about 75 percent of the time. It's not the device per se', but rather the particulars of the home in question and the quality of the AC mains inside the walls and the circuit breaker service panel.
Other solutions include wi-fi repeaters that plug into outlets around your home. I'm not a big fan of wireless repeaters because every repeat or "hop" cuts the speed in half. If your internet is slow to begin with, then a repeater can really kill the performance.
But there is a new mesh technology that looks like repeaters but don't introduce hop delays. Those solutions include EERO, Orbi, and Google Wifi, for example.
It's critical that all wireless networking devices be properly set up with encryption and keys (passwords) to prevent your neighbors from surfing on your signal. You don't need the neighbor across the back fence surfing for child porn on your internet connection! Wi-fi usually doesn't work well that far, but it may work enough for your immediate neighbor to use, especially if your wi-fi router is on the side of the home facing the neighbor. So lock it down using encryption. WPA2 is probably the best encryption mode on most home wi-fi devices.
Many wi-fi routers today have a guest mode with a separate network name and password, intended for use by guests to your home. These guest modes allow them to access the internet only using your service, but they cannot access your internal network. That way, they can't see your computer or other devices on your local area network.
Wi-Fi Away From Home
Hotels, coffee shops, restaurants, and many other public places offer wi-fi access to their guests and customers. Be careful with that. If the wi-fi network doesn't show a little padlock icon on your device, then do not use it. The padlock means the network requires a network key in order to join. This network key (or password) is required for your device's radio to connect to the encrypted wi-fi access point, just like in your home. That way, all the radio traffic is encrypted and less likely to be intercepted. No padlock means the wi-fi connection is open to all, no encryption, no permission necessary. Just like using CB radio back in the 70s -- anyone can listen in.
Even on an encrypted wi-fi network you should minimize the sites that you log into. You just don't know how secure the offered wi-fi network is in the back room although it's almost certainly safer than an open wi-fi network.
Better yet, use your own cellular connection. If you want to access the internet from your laptop, then turn on your phone's hotspot feature, and access the internet via the phone. Most phones today can do that.