Apple has launched a cheaper version of its iPhone SE as it attempts to continue normal business despite the coronavirus pandemic.

The second-generation SE resembles Apple’s previous design used for its smartphones between 2014 and 2017, complete with the traditional touch ID home button instead of face recognition. It costs from £419 in the UK and $399 in the US.

The new phone is a follow-up to the entry-level SE from 2016, which reused the design of the iPhone 5S. The new SE replaces 2017’s iPhone 8, which was until recently the cheapest iPhone on sale, costing £479 in the UK and $449 in the US.

The second-generation SE has a 4.7in retina HD LCD screen, making it one of the few smaller smartphones available. The back is glass and it has aluminium sides like the iPhone 8. It is water-resistant to IP67 standards – one-metre depths for up to 30 minutes – and has Qi wireless charging.

The new 4G phone also has the A13 Bionic chip, matching that in the iPhone 11 line, meaning the technology is not dated compared with the other current iPhones.

It has a single 12-megapixel camera on the back, supporting 4K video, and a seven-megapixel selfie camera on the front. It comes with at least 64GB of storage, with 128GB and 256GB options, and is available in black, white or red. It will launch for pre-order from 1pm on Friday and ships on 24 April in the UK.

The single camera on the back resembles that used in the iPhone XR in 2018. Photograph: Apple

Having been responsible for extending the smartphone cost ceiling beyond the £1,000 barrier, with models such as the iPhone 11 Pro Max pushing it to £1,149 and upwards, recent sales figures have consistently shown Apple’s cheapest £729 iPhone 11 model to be the bestseller.

Apple will hope the cheaper and smaller iPhone will help drive sales under the spectre of Covid-19 and upgrades from older models, particularly from those still using an iPhone 6, which is no longer supported by updates.

Quick Guide Smartphone jargon Show Size Smartphones are rated by screen size measured on the diagonal in inches. The bigger the number the larger the phone, but different phones use different ratios of height to width. How easy it is to handle comes down to the width of the phone and its weight. The narrower and lighter it is, the easier it is to hold in one hand and the less likely you are to drop it. Processor What is commonly called the processor in a phone is actually a system-on-a-chip combining the processor, graphics and other essential systems into one. Generally the newer the processor the more powerful and battery efficient it will be. Samsung, Huawei and Apple make their own, while Qualcomm is the largest supplier to other brands at the high end, with its Snapdragon 8-series range at the top. RAM The RAM (memory) is where your apps and processes are stored when in use, so the you more your phone has the better, up to a point. Android requires more RAM than iOS, so it's difficult to directly compare them. But with Android at least 4GB of RAM is currently recommended. Storage Different from memory, storage is where everything is stored on the phone, including apps and media. While a few phones can have their storage expanded with microSD cards, most cannot. That means you should aim for 64GB of storage at a minimum, but more if you want to store lots of photos. Cloud services such as Spotify or Google's Photos can help offload your music, photos or videos to the internet. Software updates Keeping your phone secure from hackers is essential, which makes software updates critical to patch bugs and security holes, as well as adding new features and improving things such as battery life and the camera. Not all phones receive regular updates. Apple's support of older phones is the best in the business of around 5 years, followed by Samsung and Google's three years, both from when the phone was released - not when you buy it. Battery life Battery life varies drastically between devices, and "all-day battery" often doesn't mean 24 hours between charges. Some may not last long enough, particularly if you're out in the evening. Battery life gets worse as the battery ages too, so a two-day battery will likely make sure the phone lasts at least a day two years later. Camera Cameras are the current battleground between the big players, but the margins between them are slimming. Most use computational photography that combines hardware with advanced software algorithms, typically allowing multiple cameras to combine to make one image. As such the camera software makes as much difference as the hardware, and is one of the few areas that actually improves over time with updates. Multi-camera systems often offer more, such as useful zooms, portrait modes and better low-light performance, but they are not all created equally. There are also 3D cameras, which can detect facial expressions and other fun tricks. The number of megapixels (MP) also makes a difference. Having more MP doesn't necessarily equal a better image, but modern smartphone cameras combine multiple pixels to improve image quality producing 12MP shots from 48MP sensors, for example. Other things to consider Wireless charging: convenient, but slower than via cable and normally a charging pad doesn't come in the box Durability: generally glass on the front and back of the phone makes it more fragile Resale value: iPhones hold their value better than most others OLED versus LCD: OLED screens emit their own light so have much deeper blacks and more vibrant colours, while LCD screens are cheaper

“The new iPhone SE has the potential to drive the next wave of adoption of Apple’s popular smartphone brand. Its aggressive pricing will challenge not only sales of new Android smartphones but is also likely to affect companies who refurbish and resell secondhand iPhones, said Ben Wood, the chief of research at CCS Insight.

Apple will be relying almost exclusively on online sales and those through network operators, given it was forced to close all its retail stores outside China on 14 March. Despite being down approximately 20% year on year, Apple’s iPhone sales in China rebounded in March to 2.5m, up more than three times from February, according to Chinese government figures, as Chinese retailers resumed operations.

But Wood cautioned: “Apple will be nervously waiting to see whether the arrival of such an affordable and well-specified iPhone will make consumers think twice about buying its premium flagship products, which, depending on configuration, can easily approach three times the cost of the new iPhone SE. History shows that iPhone purchasers seem happy to pay the premium Apple’s products command, but the current global economic uncertainty risks challenging this assumption.”