Apple discontinued last year's Apple Watch Series 4 after announcing its brand-new watch - here's how to decide between the Series 3 and Series 5

The Apple Watch Series 5 also runs on a newer processor that should perform twice as fast as the one found in the Series 3, according to Apple. The Series 5 is powered by Apple's 64-bit dual-core S5 processor, while the Series 3 users Apple's dual-core S3 processor.

The Series 5 comes with a few new features not found on the Series 3, such as a built-in compass that can show which direction you're facing when using the watch for navigation. It's also capable of taking an ECG reading through an app on the watch, which can help detect irregular heartbeats. You can also call emergency services from the Apple Watch internationally in more than 150 countries.

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The Apple Watch Series 3 lacks these features, but does offer the basics like optional LTE support, built-in GPS for location tracking, a barometric altimeter for measuring elevation, water resistance, and a heart rate monitor. (All of these features are found on the Series 5 as well).

Apple also offers more variety when it comes to colors and finishes for the Apple Watch Series 5.

The Series 5 comes in casings made of aluminum, stainless steel, titanium, or ceramic, whereas the Series 3 only comes in aluminum. You can also buy the Series 5 in silver, space gray, or gold if you opt for the aluminum or stainless steel model, titanium or space gray if you choose the titanium model, or white if you go for the ceramic version.

The Series 3 only comes in silver or space gray.

Both the Series 3 and Series 5 will support Apple's watchOS 6 software, which means they'll share almost all of the same features.

The only exceptions are features that rely on hardware not found on the Series 3, like the ability to show which direction you're facing via the compass, ECG monitoring, and watch faces that stay on even when the watch's screen isn't activated.

Both the Series 3 and Series 5 will support new features powered by watchOS 6, such as the ability to download apps directly on the watch without your phone and track activity trends over time.

The Series 3's biggest benefit is its noticeably lower price compared to the Series 5.

The Series 3 without LTE connectivity costs $200 while the cellular model is priced at $300.

The Series 5 without LTE starts at $400 — twice the price of the Series 3 base model — while the stainless steel model starts at $700. The titanium Apple Watch Edition starts at $800, and the ceramic model will cost you at least $1,300.

If you're trying to decide between the Series 3 and Series 5, it's worth thinking about exactly what you want to get out of the watch — and of course, how much you're willing to pay for it.

The Series 5 is better suited for those who may need a watch that fulfills specific use cases in addition to offering all of the basics. For example, those who may want to capture more precise data about their heartbeat rhythms and share it with their doctor should look at the Series 5 since it has an electrical heart sensor. (That's in addition to an optical heart sensor for measuring your heart rate, which the Series 3 also has.)

The Series 5 may also be the right choice for those who travel frequently and have the budget to opt for a pricier model, considering it has an integrated compass for showing your location more precisely and international emergency calling.

The other upgrades that come with the Series 5 make using the watch feel more convenient, but probably aren't worth the gap in price alone. The Series 5's screen is larger than that of the Series 3, making it easier to cram more complications on the display and therefore see more information at a glance. The display also stays on even when it's not activated, making the Apple Watch better at its most important job — telling the time.

Taken together, those changes make the Apple Watch Series 5 a much more capable smartwatch. But it's hard to compete with a watch that offers many of the same features and a similar experience for half the price.

Those who don't need specific features like a built-in compass or EKG monitoring and don't mind missing out on an always-on display will probably be just as happy with the Series 3. That older watch can still track your workouts and activity, display text messages and notifications from your phone, run apps, launch Siri on the wrist, and do almost everything else the Series 5 can.