"What does this iPhone symbol mean?" That's a question we hear a lot at Macworld. Most of the time the iPhone and iOS are wonderfully easy to use, but the iPhone does show a lot of symbols, icons and alerts. Getting to know what these symbols mean will help you to understand Apple's iOS operating system.

Here's our guide to various iOS symbols so you know what they mean. Updated, 3rd April 2014

What does it mean when an iPhone screen is showing... a lightning bolt symbol?

A little lightning bolt on the very righthand side of the status bar means the iPhone is charging.

iPhone charging icon

[Read our tips for preserving battery life on your iPhone]

What does it mean when an iPhone screen is showing... five spots (or fewer than five spots)?

The five circles on the lefthand side of the status bar (the row of icons along the top of the iPhone screen) indicate cellular strength: the more circles are filled in, the stronger the signal. 

What does it mean when an iPhone screen is showing... one, two or three curved bars?

This indicates the strength of the Wi-Fi signal. Three bars is a strong signal, two is medium, one is weak. 

iPhone signal strength icon

What does it mean when an iPhone screen is showing... eight lines spinning in a circle?

This 'spinning circle' icon (pictued above - actually it's eight lines getting lighter and darker in sequence, but it looks like a spinning circle) indicates network activity. Usually that means you're in Safari or another web browser and it's accessing (or trying to finish loading) a web page, but it could be anything that involves accessing the network.

How to stop an text message from sending

What does it mean when an iPhone screen is showing... a square with an arrow pointing out of it?

This is an action icon rather than a status icon, but it's so commonplace - and common to so many iOS 7 apps - that we thought we'd mention it.

It's the sharing icon; tap it to open the sharing palette, which will normally allow you to share the web page, email or photo you're currently browsing in various ways, such as emailing, posting on Twitter or Facebook. It's also the button you'd press to save a photo sent to you in WhatsApp or shared via Photo Streams to your own Camera Roll.

What does it mean when an iPhone screen says... 3, 02-UK, AT&T, Verizon, T-Mobile, Sprint or similar?

It seems obvious when you write them all out together like that - they're telecoms carrier firms, and your iPhone is simply displaying the name of your carrier between the signal strength circles and the Wi-Fi strength bars. You may notice it change when you go abroad and the device picks up an overseas provider.

But people sometimes get confused by the number 3 on its own - is my iPhone telling me it's on 3G, or that the signal strength is 3 (out of 5?) or something else? Nope. Your carrier is 3, that's all.

iOS 7 status bar

The iOS 7 status bar along the top of the screen indicates (from left to right): a moderate cellular signal (3 out of 5); that my carrier is 3; a strong Wi-Fi signal (3 out of 3); Do Not Disturb mode is on; Bluetooth is on; the battery is at 58% capacity; and we are charging.

What does it mean when an iPhone screen is showing... a plane icon?

You've got Airplane mode switched on. This mode blocks all Wi-Fi and cellular connections so you won't be able to receive or make calls, send texts, access the internet and so on. It's designed for use on planes, as the name suggests.

In iOS 7 you can switch Airplane mode on and off in the Control Centre - swipe upwards from the Home screen and tap the plan icon there. In iOS 6 and earlier you need to turn it off from the Settings app.

What does it mean when an iPhone screen is showing... a clock icon?

It simply means you've got an alarm set. To edit your alarms, open the Clock app and tap Alarm in the bar along the bottom. (You can access the Clock app from the Control Centre in iOS 7 - it look a bit like a stopwatch.)

What does it mean when an iPhone screen is showing... a telephone handset with an arrow pointing to the right?

This means call forwarding is enabled. You can adjust call forwarding under Settings, Phone, Call Forwarding.

What does it mean when an iPhone screen is showing... a padlock with a circled arrow around it?

Orientation Lock

The iPhone orientation is locked so apps that support horizontal and vertical modes (like iBooks) will be locked to one or the other. Slide your finger up from the bottom of the display to open Control Centre and tap on the Orientation Lock icon (same shape) to to turn it off

See: Apple jargon buster: tech terms explained, in Macworld's glossary of technical language

What does it mean when an iPhone screen is showing... an E symbol?

This means you are on an Edge network rather than one of the newer 3G, LTE or 4G networks. Apps like Safari that use the Internet may run a little slowly, but you should be able to use them (along with apps like Mail and Maps) just fine.

Edge Symbol

What does it mean when an iPhone screen says... GPRS?

This means you are using an aging GPRS (General Packet Radio Service) network to access the internet. Internet services and apps will work, but so slowly you might think they aren't. Try to connect to a Wi-Fi hotspot or move to a different area to get a better signal.

GPRS

What does it mean when an iPhone screen is showing... a crescent moon symbol?

Do Not Disturb mode is turned on. Do Not Disturb is an iPhone mode that blocks unwanted phone calls and alerts (although you can set exceptions - you can choose for those who call repeatedly to be put through in case it's an emergency, for example, or to accept calls from those on your VIP list). Slide your finger up from the bottom of the display to open Control Centre and tap the Do Not Disturb icon to switch this mode off.

Do Not Disturb

See: Apple's iPhone iOS Do Not Disturb feature oversleeps on New Year’s Day

What does it mean when an iPhone screen is showing... a small telephone with dots beneath it?

This means that the iPhone’s TTY (Teletype) service is active. TTY is a service that enables people with poor hearing to interact with phone calls. Sometimes inserting a SIM card from an unknown carrier turns TTY on by default. Tap on Settings > Phone and set TTY to Off.

TTY

What does it mean when an iPhone screen is showing... VPN inside a box?

You're connected to a network using VPN (Virtual Private Network). This is where you browse to a small virtual network (which passes everything on from the wider internet). If you work for a larger company they may run their own VPN network, and you’ll need to be connected to one to use their services (like Contacts) on your phone. If not click on Settings > General > VPN and set VPN to Off.

VPN

What does it mean when an iPhone screen is showing... two linked circles that look like a paperclip icon?

You have set up a Personal Hotspot and are sharing your internet connection from your iPhone to another device. This can be handy if you are using an iPad or Mac without its own internet connection, but if you’re not doing this you should turn it off. Tap on Settings > Personal Hotspot and set Personal Hotspot to Off.

Hotspot

See: Make your iPhone a Personal Hotspot - cost round up

What does it mean when an iPhone screen is showing... an arrow symbol?

This means that one of your apps is using Location Services to pinpoint your location. Often an app like Maps will use Location services, but some apps like Motion GPSX track your location. Tap on Settings > Privacy > Location Services to see which apps are allowed to access Location Services.

Location Services

What does it mean when an iPhone screen is showing... a symbol made of triangles and lines that looks like a runic letter B?

Sorry for the long-winded explanation, but this one's hard to describe!

The runic capital B means Bluetooth is turned on. Bluetooth is used to communicate with other devices, like wireless earphones, speakers and external keyboards. Slide your finger up from the bottom of the display to open Control Centre and tap the Bluetooth icon to turn it Off.

(Thematically, a Norse-esque runic look was chosen for this icon because Bluetooth was named after Harald Bluetooth, a Viking king; the icon itself is a 'bind rune' that combines Harald's initials. For more information, take a look at 'So, that's why it's called Bluetooth!' and other surprising tech name origins.)

Bluetooth Settings for Pure Evoke D2

What does the i in iPhone stand for?

Unofficially the i stands for internet. It originally comes from the iMac computer, which was launched in 1997. The iMac was designed to make it as easy as possible to connect to the internet. Watch this '3 Steps' advert to see Apple promoting this idea. The 'i' was then added to other products like the iPod, iTunes, iMovie and other products. Eventually, it became a shorthand way of saying 'Apple Product'. Officially it no longer stands for anything.

What does it mean on an iPhone when... three dots appear after I send a text message?

The three dots appear when somebody is reading and replying to your text message. If the dots disappear, it's because they have stopped typing. This means you can see when you are in a conversation with somebody, as opposed to waiting for them to reply

See also: Get to know iOS 7: Phone, FaceTime, and Messages

What does it mean when an iPhone screen is showing... two arrows in a spinning circle?

This is the sync icon, and it signifies that the iPhone is currently syncing with a computer. The iPhone can sync wirelessly, so it no longer has to be attached to the computer. This isn’t a bad thing but if you want to stop this happening connect your iPhone to your Mac using the Lightning Cable, open iTunes and click on your iPhone in Devices and untick Sync with this iPhone over Wi-Fi.

See also: How to sync your iPhone with iTunes wirelessly