Black Friday has become a worldwide phenomenon. Coupled with Cyber Monday, Black Friday offers incredible deals from multiple retailers online and in-store. The main action happens on just one day, but there are plenty of bargains to be had on the build-up too.

That action has already started, with many retailers offering great prices on a range of products, but there's plenty more to come. Here's everything you need to know about Black Friday 2017 in the UK

Originally a US-only event, Black Friday has stretched across the pond and to other regions too. It is a day in November, the day after the US holiday of ThanksGiving, where retailers heavily discount thousands of items in the build up to Christmas.

It lasts an entire day traditionally, but some retailers start their Black Friday deals early, including Amazon in the US and UK, which often starts its sales period a week beforehand. Black Friday is followed by Cyber Monday - an online event the Monday after that essentially carries on the bargains for an extra day.

In 2017 Black Friday takes place on Friday 24 November. Cyber Monday will be held on Monday 27 November.

There are deals across so many areas, we're listing some of the best here, but we're also rounding them up by category to help you find what you're looking for. So, either browse below, or click through to one of these features if there's something specific you want to buy:

Amazon started its Black Friday deals on 17 November and running them beyond Black Friday itself, to Sunday 26 November. There will be daily deals, as well as long-running deals. Here are some of the best:

Argos runs deals all through the year, but Black Friday is a time to get something special. There are great bargains on tablets, TVs and games consoles but there are cheaper goods to be had in almost every category it covers.

Boots might not be top of your list for the latest electronic, but if you're after grooming products or something else healthcare related, it's a good place to start Christmas shopping. It generally has sales for just the one day, so you need to be quick.

Carphone Warehouse always offers a range of deals on mobile devices, tablets and accessories. It runs its Black Friday bargains for 24 hours, both in store and online.

Currys/PC World has already kicked off its Black Friday sales event. Check out some our favourite deals here:

eBay is the land of deals for many, be that new from store outlets, or from individuals who have something that you want, but they don't. Traditionally, there a full range of deals available through eBay, and although they haven't specifically been positioned as Black Friday deals, it's always worth looking. Games consoles, in particular, were very cheap last year.

EE's Black Friday usually takes the form of some major deals on handsets, although you can also get bargains on price plans and PAYG deals too.

John Lewis has a commitment to be "Never Knowingly Undersold" so, as the site points out, it has to "match competitors' prices". The advantage with John Lewis is that it offers aftercare and often guaranteed cover for five years for many products, which is ideal for big gadgets like TVs or laptops.

The John Lewis Black Friday deals will start at midnight on 23 November, we expect.

Game starts pushing a range of offers on consoles and games early, but you can expect some even bigger deals come Black Friday. Generally these take the form of extra games added to bundles, if you're looking for a new machine.

With the Xbox One X coming out prior to Black Friday, it might be worth hovering over Game's site on the day for any bundle deals for the new console.

Marks & Spencer generally jumps on board the Black Friday bandwagon, although there doesn't tend to be that much technology on its site. However, it does sell a range of activity trackers and other items, and has formerly offered great deals on Fitbit, for example.

Mobiles.co.uk is part of the Dixons Carphone group and a strong competitor when it comes to price. It has some great offers on the day and will no doubt soon add a page where you can be notified of any deals.

O2 isn't a big Black Friday participant but could be tempted to offer some major discounts this year considering its competitors will.

TalkTalk has taken the unprecedented step of starting its Black Friday deals a month early. It is heavily discounting its fibre and standard broadband packages until 2 November 2017, and as customers can fix their prices for 18 months, you'll be able to stick to the discounted price for a year-and-a-half.

A TalkTalk Fast Broadband package offers up to 17Mbps speeds for £19.95 a month. There are no set-up fees (usually £60) and you get a free TalkTalk Super Router. It also includes line rental.

If you want faster speeds, the TalkTalk Faster Fibre deal could be up your street. It costs £25 a month for speeds up to 38Mbps. Set-up is again free, as is the router, and line rental fees are included.

Tesco usually has a countdown time on a dedicated Black Friday site soon before the day kicks off. Last year, it also gave you the opportunity to the latest offers in advance, as well as register as a new customer to make sure you're ready to go when the clock hits zero.

Tesco Black Friday deals usually last a week or so.

Three always has something planned for Black Friday, promising lots of deals on the big day.

And prior to the event you will be able to sign up for details. We'll let you know when that option is available.

Vodafone will be taking part in Black Friday for the fourth year, we expect. It also ran a countdown clock on its site prior to the day so it's more than likely to do the same again.

It offered great deals on phones and tablets in 2016, so fingers crossed.

Dyson, manufacturer of high-end vacuums, lighting, driers and fans always slashes prices for Black Friday. It will even start its deals before Black Friday, if last year is anything to go by.

HTC has long been taking part in Black Friday and, this year, will be starting to offer deals early. It has announced that its Black Friday deals page will go live on 20 November and run through until Monday 27.

You can sign up for a newsletter to be sure to get the information early doors, but these are the deals it will be offering:

These deals will be live at 10:00 on 20 November until 23:59 on 27 November (while stocks last):

  • HTC U11+ for £629 (10 per cent off with pre-order)
  • HTC U11 Life for £314 (10 per cent off with pre-order)
  • HTC U11 (128GB) for £519 (20 per cent off)
  • HTC U11 (64GB) for £479 (20 per cent off)
  • HTC U Ultra for £359 (20 per cent off)
  • HTC 10 for £319 (20 per cent off)
  • HTC Desire 10 Lifestyle for £183 (20 per cent off)
  • HTC A9s for £159 (20 per cent off)

Samsung always offers plenty of bargains across its online store. There's no indication that this year will be any different.

We will be updating highlighted deals across retailers and brands as and when they go live, both in the build up to Black Friday, the day itself and throughout Cyber Monday.