EDIT: Today is the day of Samsung's Galaxy Unpacked event, where the Galaxy Z Fold 3 is expected to be announced; check out our Galaxy Unpacked live blog or learn how to watch the event.

The Samsung Galaxy S21 Ultra established itself this spring as Samsung's ultimate phone, offering the best features the electronics giant has to offer in a cell phone. However, the S21 Ultra has a new rival in the form of the Galaxy Z Fold 3.

Normally, Samsung's main internal rival to the latest Galaxy S phones would be the latest Galaxy Note. However, since the Galaxy Note 21 will not be introduced this year and Samsung's latest foldable has been deprived of some of its defining features, the S21 Ultra has a new competitor.

In addition to the diversions from the Note series, many of the high-profile features found on the Galaxy S21 Ultra (powerful processor, dynamically adjusting refresh rate screen, even S Pen support) are found on the Galaxy Z Fold 3.

In this Samsung Galaxy Z Fold 3 vs. Galaxy S21 Ultra roundup, we will look at the similarities between the two flagship devices and how Samsung differentiated the two more feature-packed products. [At $1,200, the Galaxy S21 Ultra is quite expensive for a phone. But the Galaxy Z Fold 3, at $1,800, is an even bigger investment, albeit slightly cheaper than the Galaxy Z Fold 2 at launch.

The S21 Ultra will be available for purchase starting in January; the Z Fold 3 is available for pre-order now, but will not go on general sale until August 27.

While the two phones are obviously related, the S21 Ultra and Z Fold 3 have very different shapes; the S21 Ultra is a large 6.8-inch phablet phone, much like other modern smartphones; the Z Fold 3 is a book-shaped foldable phone with a " Flex Mode" hinge, which allows it to be opened at any angle.

As for the display, the S21 Ultra has a single 6.8-inch panel; the Z Fold 3 has a regular-sized 6.2-inch display on the front and a larger 7.6-inch display inside when opened. All of these are OLED screens with variable refresh rates of up to 120 Hz.

However, the S21 Ultra is the tougher phone. It has Gorilla Glass Victus to protect the display and IP68 dust and water resistance to prevent damage to internal components.The Z Fold 3 uses the same Victus glass for the outer display, but with a more delicate plastic and glass laminate on the inside, easily scratched if not cared for. The water resistance of the foldable is IPX8, but Samsung makes no promises about dust entering the phone's mechanism.

The Galaxy S21 Ultra is one of the best camera phones and should remain Samsung's camera king after the release of the Galaxy Z Fold 3.

The two phones have the same amount of cameras, but for very different purposes: on the back of the Galaxy S21 Ultra is a 108MP main camera, a 12MP ultrawide camera, and two 10MP telephoto cameras (one with 3x optical zoom, the other with 10x optical zoom) The Z Fold 3's rear camera is inferior to the Z Fold 3's rear camera, which consists of a 12MP main camera, an ultrawide camera, and a 2x optical zoom telephoto camera.

The only front camera is a single 40MP selfie camera located in a punch hole in the center of the S21 Ultra's display. The Z Fold 3, however, has two selfie cameras: the first is in the punch hole notch of the front display and has a resolution of 10 MP; the second is hidden under the inner display and has a resolution of only 4 MP. This means that the view is unobstructed when viewing content on the large screen, but may result in significantly poorer photo quality.

The two phones are competitive in terms of default specs; both the S21 Ultra and Z Fold 3 use the Snapdragon 888 chipset and combine 12GB RAM and 256GB storage.

The Z Fold 3 only has the option to increase storage to 512GB. However, the S21 Ultra has a cheaper 12GB/128GB option and a more expensive version with 512GB storage with 16GB of RAM up.

The S21 Ultra wins in battery capacity; the Z Fold 3 has a dual-battery system that only holds a total of 4,400 mAh, while the S21 Ultra can hold up to 5,000 mAh. However, both models have the same charging specs: 25W wired charging, 10W wireless charging, and 4.5W reverse wireless charging.

Both models run Android 11 running on Samsung's One UI, but the Z Fold 3 version is significantly different due to the additional display. This includes the ability to open multiple apps at once, use a static taskbar like a Windows or Mac computer, or open certain apps to the entire internal display to access additional features.

Both models support their own S Pen stylus, which must be purchased separately and can only be attached to the phone if a compatible case is purchased. S Pen Pro" and the Bluetooth-enabled "S Pen Pro".

These two Samsung flagships are two very different ways to spend your money; the S21 Ultra is the most refined experience and has the most performance and photography capabilities, but is still a regular phone most of the time you use it. The Z Fold 3 has a dual display and hinge system and is far more versatile, but you'll pay $600 more to get it.

Most users will be happy with the S21 Ultra. But without waiting for a full review, the Z Fold 3 will be a truly special experience for users who decide to buy it.