Editors' note: This post is part of a series and is regularly updated. For the other parts, check out the related stories below.
Wi-Fi and internet are two different things. Let me say it again: they are two different things.
For years now, the term Wi-Fi has often been synonymous with access to the internet. Most of us use "Wi-Fi" as a shortcut to mean our home broadband internet connection. And when you're traveling, free Wi-Fi is understood as free internet since that's the only reason you use Wi-Fi when out and about.
In this post, I'll clarify the difference between the two often-confused terms and provide answers to other connection-related questions. Among other things, knowing the difference between Wi-Fi and internet connections can help you troubleshoot problems at home, purchase the right equipment for your network, and most importantly, understand the risk of using a free Wi-Fi network.
As mentioned in the first part of this series, Wi-Fi is simply an alternative to network cables as a way to connect devices of a local area network (LAN). Prior to Wi-Fi the only way to connect devices together was to run physical network cables between them, which can be inconvenient. Wi-Fi allows devices to connect to one another the same way as when network cables are used, just without the actual cables. A Wi-Fi network is basically a wireless local network.
The owner of the Wi-Fi network is in total control. She can change the name of the network, the password, the number of connected clients, allowing them to exchange data with one another or not, and so on. Even the Wi-Fi router or access point itself can be changed or turned on or off any time.
A home Wi-Fi network, which is almost always hosted by a router, is independent from the internet. Meaning that any devices on the network can always work with one another to share and back up data, print, stream local media and so on. A connection to the internet, however, enables them to also access internet-based services, such as Skype, Netflix, news, Facebook, Twitter and other services.
To connect a home Wi-Fi network to the internet, the router needs to be connected to an internet source, such as a broadband modem, via its WAN port. When this link is complete, the Wi-Fi signal of the local network will also provide a connection to the internet for any device connected to the network. So Wi-Fi is just one way to bring the internet to a device. And this also explains why sometimes your Wi-Fi signal is at full strength, yet you still can't access the internet.
Generally known as the wide area network (WAN), the internet connects computers from around the world. In reality, the internet actually connects many local networks together, via a ton of routers. With the internet, your home local network is no longer secluded but becomes part of one giant worldwide network.
The internet connection is generally beyond the control of the users. Other than turning it on or off, the only other thing you can do is pay for the desired connection speed and hope you get what you pay for. Internet speed has progressively increased in the last decade. Ten years ago, a fast residential broadband connection generally capped somewhere between 1.5Mbps to 20Mbps; now it's between about 50Mbps to 150Mbps and even faster.
That said, most of the time, the speed of the internet is still slower than that of a wired local network, which is either 100Mbps or 1,000Mbps. For a Wi-Fi network, the speed of the local network depends on the standards used by the Wi-Fi router (or access point) and the connected clients, and can sometimes be slower than a fast broadband wired internet connection.
What does this imply?
Now that you know the difference between Wi-Fi and internet, here are a couple of takeaways:
Just because you have Wi-Fi doesn't necessarily mean you have internet access. Also, having a strong Wi-Fi signal doesn't always translate into fast internet speed. In fact, to know how fast your internet speed is, in most cases, you need to test it independently from Wi-Fi.
That said, keep in mind that if you use Wi-Fi to share the internet, then it's the internet speed that you want. In this case, Wi-Fi is just the vehicle that carries internet to your device. This means if all you care about is a full Wi-Fi signal, then you're missing the point. Take Wi-Fi extenders, for example. These devices wirelessly extend the coverage of an existing Wi-Fi network. Each time the Wi-Fi signal is extended, there's a 50 percent signal loss. This means if you have a few Wi-Fi extenders, by the time the signal gets to the device you're using, there's not much "internet" left for a fast, stable connection. The best way to extend your Wi-Fi network is use multiple access points that connect to the main routers via network cables. If running cables is not an option, then be sure to have no more than one Wi-Fi extender in a network.
Most importantly, when you're connected to an unknown Wi-Fi network (such as one you see popping up on your phone or laptop when you travel), keep in mind that because you need to access their router to get on the internet, the owner of that Wi-Fi network can potentially see all the information you're sending and receiving, including usernames and passwords. That said, when using free Wi-Fi, unless you're accessing a secure website (one in which the address, or url starts with https) don't type in any sensitive information. Better yet, refrain from doing any online banking using free Wi-Fi. Also keep in mind that public Wi-Fi from known entities, such as an airport or an office, is generally more secure than a Wi-Fi network at a random cafe. An open Wi-Fi network, one that requires no password or agreement of terms of service to use, is the most risky.
Types of broadband internet connections
Wired internet (aka residential broadband): This is when you connect to the internet using a physical cable, be it a telephone line (DSL) or a cable line (cable), or a fiber optic line (FIOS). This type of internet connection is fast (especially cable and FIOS), affordable, and is the most popular. A wired internet connection generally comes with no data caps or at least very high caps, so users don't need to worry about how much they download or upload.
Satellite internet (aka satellite broadband): This is similar to the wired internet but instead of connecting to the service provide via a cable, the home network connects to a satellite dish on the roof. The dish then communicates with satellites to provide the internet access. Satellite internet tends to be slightly more expensive and slightly slower than wired internet but is still an affordable option for remote areas with no cable, DSL or FIOS services.
Cellular internet is generally expensive because it tends to come with monthly data caps and customers have to pay more than the fixed monthly cost when they go over the allowance. This type of internet access is very popular with mobile devices, including smartphones and tablets. There's also another popular type of this connection, called mobile hot spot, which is a mini Wi-Fi router that connects to a cellular network and broadcasts a Wi-Fi signal to let more than one Wi-Fi-enabled device share a single cellular connection. Many smartphones can also work as mobile hot spots; on the iPhone for example, this is called Personal Hotspot and can be turned on in the phone's settings.
Question: My Wi-Fi connection is very strong (full bars) but I still can't stream YouTube video without long delays. I often even have to wait for a long time for a website to load. Why?
Answer: This is because the Wi-Fi signal is different from the internet speed, which is what decides the quality of your internet experience. It's likely that you either have a slow broadband connection, or your Wi-Fi network is ineffective in carrying internet (i.e. there are too many Wi-Fi extenders being used.) You should check your internet connection, and then make sure your Wi-Fi network is optimally set up.
Q: My broadband internet connection is at least 50Mbps when I connect via a network cable, but via Wi-Fi it's only about 20Mbps at most. Why?
A: This is normal, since the real-world sustained speed of all Wi-Fi standards is much slower than the ceiling speeds. The Wi-Fi speed also changes depending on how far you are from the router. On top of that, you might have a legacy Wi-Fi router or your device uses a legacy Wi-Fi adapter. However, 20Mbps is fast enough for almost any internet-based applications.
Q: If I plug my PC directly in to my cable modem, I get the full 150Mbps download speed that I pay for, but when I connect via my router, still via a network cable, I get only 40Mbps. What's wrong?
A: This is likely because you use a router that has a Fast Ethernet (10/100) WAN port. Try a a Gigabit router.
Q: I use Speedtest.net to test my internet connection and the results change dramatically between different test servers. How do I know what the speed of my internet connection really is?
A: Take the best result as your official internet speed. This happens because the connection speed depends on how far the test server is, how busy the server is at the time of testing, and how many bridges the test data has to cross to get to your computer. Generally, the test result changes based on the ping time (how long it takes for information to do a round trip between the server and your computer), with the shorter ping yielding faster connection. Your connection, however, should be measured by the speed at which it connects to the server that yields the highest result.
Q: My internet speed is very fast, both via wired and Wi-Fi connections, but sometimes it still takes a long time for me to download a relatively small file. What's the problem?
A: Having a fast internet connection doesn't guarantee an all-around good internet experience. This is because the internet is a community, and the interaction between any two parties depends on both. If you download a file from a party with a slow connection to the internet, the downloading process still takes a long time, and unfortunately, there's nothing you can do about it.
Q: I have cable internet with 30Mbps download and 6Mbps upload. Things are going well generally but sometimes when I upload a large file, my download speed also becomes very slow. Is this normal?
A: Yes, downloading and uploading work together. Information is transferred via the internet in packets. Each time a packet is received, the receiving end needs to send back a confirmation before it can receive the next packet. When you upload a large amount of data, there's not much bandwidth left for the computer to send the confirmation back to the server, which in turn slows the download speed.