What is Android? Well, there\u2019s a few reasons why you might be asking yourself that question. The scenario that springs to mind is that you\u2019re out of contract, looking for a new mobile phone and you keep finding these sections on Vodafone, O2 and pals that refer to some kind of smartphone spearheaded by a friendly looking green robot.Chances are that what you really wanted was an iPhone but soon discovered that it\u2019s well over budget and you\u2019re currently in the market for alternatives. There\u2019s BlackBerrys but somewhere between the business connotations and the steam-rollered mobile phone look, you\u2019ve never quite fancied it. So, is this Android thing a good idea and just what the hell is it anyway?\nFirst let\u2019s make this simple. Android is a mobile OS or operating system. Technically speaking, it\u2019s a software stack, one of whose components is an operating system, but let\u2019s ignore that for the sake of argument. Essentially, it\u2019s the piece of software that runs the show, much like iOS is for the iPhone and Windows is for the majority of laptops out there. For the latter examples, they\u2019re owned and maintained by Apple and Microsoft respectively but in Android\u2019s case - although not to the same extent - it\u2019s all about Google.Brief HistoryAndroid was first developed in 2003 by Android Inc. which consisted of Nick Sears, Chris White, Rich Miner and Andy Rubin, the last of whom is still in charge of the project today. The idea behind it, in Rubin\u2019s own words, was to create \u201csmarter mobile devices that are more aware of its owner's location and preferences\u201d.\nIn 2005, obviously impressed by what was going on down the road in Palo Alto, California, Google stepped in to acquire the company, leaving Android Inc. a whole subsidiary within the Internet giant. It wasn\u2019t long before people put two and two together and realised that Google\u2019s arrival into the mobile phone space was soon to come. All the same, the world had to wait until 21 October 2008 for Android to arrive when it launched in the US in conjunction with T-Mobile and HTC on a device known as the HTC Dream or T-Mobile G1 which became the very first Android powered smartphone.Open SourceAndroid is what\u2019s known as open source and, to a large degree, that means that its inner workings and machinations are free to for the public to access, view and even tinker with. Now that doesn\u2019t mean that Android phones are the preserve of developers and heavy geeks, and it doesn\u2019t mean that Android phones are complicated to use - far from it - it\u2019s simply a facet of the project in general. So, if you felt like it, you could download yourself a copy of it, write your own bits and pieces in and try to put it on your old Atari ST or what have you. According to the licensing, you couldn\u2019t then plaster your old 16-bit system with the Android and Google logos and trademarks or officially call it an Android device but it would be perfectly legal otherwise.What you need to knowTo say that Android is a cheaper alternative to iPhone OS is unfair but it\u2019s also true. The phones that run it are cheaper and it\u2019s not a million miles away in terms of experience and design. To do it it\u2019s dues, however, Android is also a choice. For a few it might be a second prize option but for most it\u2019s a preference.CustomisationIn keeping with the ethos behind the project, Android does not leave the user at arms\u2019 reach. You can customise the experience by adding whatever kind of wallpaper and widgets you like to the five home screens available on the current version of the software. You can also create and arrange shortcuts to web pages and applications, much as you can the desktop of your computer. On top of that, there\u2019s also the traditional app grid you\u2019d expect to find on most smartphones these days.Look and feelAs part of the Google licensing, just about all Android phones come complete with four buttons (home, menu, back and search) and multitouch capactive screens for all your pinching and zooming as made famous by the iPhone.\nThat said, one of the tricky things about the Android experience is that it\u2019s far from uniform from device to device. Rather than become slave to someone else\u2019s software, what many of the hardware manufacturers like to do is put their own custom user interface on top of the basic Android look. Sometimes that\u2019s a good thing and sometimes it\u2019s more of a hindrance than anything else, but if you\u2019d rather avoid the custom UI altogether then the word to look out for in the smartphone field is \u201cNexus\u201d. The Nexus One and Nexus S phones offer the pure, unadulterated Android experience.Either way, a custom UI will not keep you from the some of the best features of the system which include tethering over both Wi-Fi and USB, meaning that you can pick up the Internet on your laptop so long as you have your Android phone with you, and the fact that you can use voice entry for every single field anywhere on the phone.AppsLike all good smartphones these days, the Android system does allow you to download third party apps. So whether that\u2019s Angry Birds or Bump, you\u2019ll find just about everything on the 200,000-strong Android Market.While there are a handful of omissions - no Hipstamatic, for example - there are also a good glut of Android-only apps such as Google Gesture Search, which allows you to flick through your phone\u2019s contents by drawing on the screen, and Listen, Google\u2019s podcast service. In fairness, apps tend to come to iPhone first but you\u2019ll certainly find what you\u2019re looking for, or at least a version of it.DevicesMuch like iOS, it\u2019s not just phones where you\u2019ll find Android. There\u2019s also media players out there that use it as their OS as well as, more recently, tablets too. HTC, Samsung and LG, Sony Ericsson and Motorola, to a lesser extent, are some of the major players manufacturing Android devices and you can expect almost all of them out there to carry all the gyros, accelerometers, magnetometers, proximity sensors, light sensors, pressure sensors, GPS and everything else you\u2019d expect to find on a top end piece of kit.VersionsMuch in the same way that Windows has evolved from Windows 3.11 to Windows 95, Windows XP and so on, Google has also released new versions of Android since launch - each for free and each containing new features and bug fixes. The updates are named after a different dessert item alphabetically with the first being Cupcake and the most recent two Gingerbread and Honeycomb. These updates are issued by Android and will come straight to your device over the air via either your operator, which might want to check it first, and possible via your manufacturer as well - especially if your hardware supports a custom UI which will itself need an adjustment in order to fit.\nIf a delay between the release of a new version and you receiving it is something that bothers you, then a pure Android OS on a handset bought SIM-free is the way to go.ProblemsWhile there are plenty of reasons to pick an Android device ahead of all the others, they also come with drawbacks as well. Most of these stem from the fact that, unlike with iOS, there are many manufactures out there making lots of different devices for a piece of software made by someone else. In other words, with Google having to combine with HTC, Samsung and all the others, there isn't that that same one company synergy as you get with Apple and its products.\nThe upshot is that you get an experience that isn\u2019t quite as tight nor quite as reliable. It crashes just a little bit more than iOS and certainly more than BlackBerry. The apps also tend to force close a little more often and sometimes the odd one will not work at all simply because the restrictions on the Android Market are not as stringent and the development sometimes not as strong.\nProbably the most serious criticism levelled at Android is often its continued fragmentation. Not all of the devices out there can run all of the apps. That\u2019s largely owing to both the Android version updates and the increase in spec of the newer devices as time goes by. As a result, developers can\u2019t and don\u2019t always keep up with making sure that a phone bought in 2008 running one of the older systems is catered for.All the same, Android isn't the best selling phone software on the market at the moment for no reason. With over 350,000 new Android phone activations each day, it seems that the world has decided that the positives of this platform by far and away outweigh the negatives.Check out more from Android Week and head over to our reviews if you're looking for a little buying advice.