The Samsung Galaxy S21 Ultra, released in January 2021, is a flagship smartphone that showcases the best in hardware, software, and camera technology. Below is a detailed description of its key features:

Design and Build Quality:

• Dimensions: 165.1 x 75.6 x 8.9 mm (6.5 x 3.0 x 0.35 in)
• Weight: 228g (8.0 oz)
• Materials: The phone features a premium build with an aluminum frame, glass front (Gorilla Glass Victus), and a glass back (also Gorilla Glass Victus) for enhanced durability.
• Display Protection: Corning Gorilla Glass Victus for protection against scratches and drops.
• Colors: Phantom Black, Phantom Silver, Phantom Titanium (limited edition), Phantom Navy, and Phantom Brown.

The phone has a sleek, modern design with a prominent camera bump at the back that houses four lenses. The front is almost entirely occupied by the 6.8-inch Dynamic AMOLED 2X display, and it has an edge-to-edge design with slim bezels.

Display:

• Type: 6.8-inch Dynamic AMOLED 2X, 120Hz, HDR10+ certified.
• Resolution: 1440 x 3200 pixels (~515 ppi density).
• Refresh Rate: Adaptive 120Hz (which adjusts between 48Hz to 120Hz depending on the content).
• Brightness: Peak brightness of 1500 nits for great outdoor visibility.
• Aspect Ratio: 20:9 for an immersive viewing experience.
• Protection: Corning Gorilla Glass Victus.
• Features: The display supports a 120Hz refresh rate, HDR10+, and deep color contrast, making it ideal for gaming, watching videos, and general use.

Performance:

• Chipset (Varies by Region):
  • USA/China/India: Qualcomm Snapdragon 888 (5nm).
  • Global (Exynos 2100 for most regions): Samsung’s own Exynos 2100 (5nm).
• CPU:
  • Snapdragon 888 - Octa-core (1x 2.84 GHz Cortex-X1, 3x 2.42 GHz Cortex-A78, 4x 1.80 GHz Cortex-A55).
  • Exynos 2100 - Octa-core (1x 2.9 GHz Cortex-X1, 3x 2.80 GHz Cortex-A78, 4x 2.2 GHz Cortex-A55).
• GPU:
  • Snapdragon 888: Adreno 660.
  • Exynos 2100: Mali-G78 MP14.
• RAM: 12GB or 16GB LPDDR5.
• Storage: Available in two configurations – 128GB, 256GB, and 512GB UFS 3.1 (non-expandable storage).

This powerful hardware setup allows the Galaxy S21 Ultra to perform exceptionally well with multitasking, gaming, and heavy applications.

Battery:

• Capacity: 5,000 mAh, non-removable.
• Charging:
  • Wired Charging: 25W fast charging (USB Power Delivery 3.0).
  • Wireless Charging: 15W wireless charging.
  • Reverse Wireless Charging: 4.5W (Wireless PowerShare) to charge other devices like earbuds or phones.

The battery supports full-day usage even with the 120Hz refresh rate and large display, though heavy users might need to recharge before the end of the day.

Camera System:

The camera system is one of the standout features of the S21 Ultra. It has a versatile and powerful quad-camera setup:

1. Main Camera:

   • 108MP, f/1.8, 26mm (wide), Dual Pixel PDAF, OIS.
   • This is the flagship sensor capable of 12-bit RAW image capture with high dynamic range and exceptional detail.

2. Telephoto 1 (3x Optical Zoom):

   • 10MP, f/2.4, 72mm (telephoto), PDAF, OIS.
   • Offers 3x optical zoom for sharp and detailed zoom shots.

3. Telephoto 2 (10x Optical Zoom):

   • 10MP, f/4.9, 240mm (periscope telephoto), PDAF, OIS.
   • Supports 10x optical zoom and up to 100x Space Zoom (digital zoom).

4. Ultra-wide Camera:

   • 12MP, f/2.2, 120˚, 13mm (ultra-wide), Dual Pixel PDAF.
   • Captures wide-angle shots with great clarity and minimal distortion.

5. Selfie Camera:

   • 40MP, f/2.2, 26mm (wide), Dual Pixel PDAF.
   • Features a high-quality 40MP sensor, allowing for sharp and detailed selfies.

Key Camera Features:

• 8K Video Recording: Records at 24fps in 8K resolution, which is the highest video quality available on a smartphone.
• 4K Video: Supports 4K at 30fps and 60fps with HDR10+ and OIS.
• Super Steady Video: Enhanced stabilization for smooth video capture even in motion.
• Space Zoom: Supports up to 100x digital zoom with a relatively stable image.
• Director's View & Single Take: Features that allow for dynamic video recording with multiple perspectives or capture of multiple types of content in one shot.

Software:

• Operating System: Samsung One UI 3.1 based on Android 11 at launch, with upgrades available.
• Features:
  • Samsung’s One UI offers a user-friendly interface with customizable themes, smooth animations, and additional features such as Samsung DeX for desktop-like experience, split-screen multitasking, and improved app functionality.

Connectivity:

• 5G Support: Both Sub-6 GHz and mmWave (for the USA) 5G support, providing fast data speeds.
• Wi-Fi: Wi-Fi 6 (802.11 a/b/g/n/ac/6), dual-band.
• Bluetooth: 5.2.
• NFC: Yes, for mobile payments.
• USB: USB Type-C 3.2.
• Other: Dual SIM (Nano-SIM and eSIM), GPS, GLONASS, GALILEO, and NFC.

Security:

• Fingerprint Sensor: Under-display ultrasonic fingerprint sensor.
• Face Recognition: 2D facial recognition via front camera.
• Security Features: Samsung Knox security suite for enhanced protection.

Other Features:

• Water and Dust Resistance: IP68 rating (up to 1.5 meters for 30 minutes).
• Stereo Speakers: Tuned by AKG with Dolby Atmos support, providing immersive sound quality.
• S Pen Support: Although not included in the box, the S21 Ultra supports the S Pen, which is sold separately, making it a powerful option for productivity.
• No microSD card slot: Unlike some older Galaxy devices, the S21 Ultra doesn’t offer expandable storage.

Price and Variants:

The S21 Ultra was released at a premium price, with variants depending on RAM and storage configurations:

• 12GB/128GB
• 12GB/256GB
• 16GB/512GB

The pricing varied by region, but it started at around $1,199.99 for the base 12GB/128GB model at launch.

Conclusion:

The Samsung Galaxy S21 Ultra is one of the most feature-packed smartphones ever made, offering flagship-level performance, stunning display quality, and an exceptional camera system. It appeals to users who demand the best in both everyday use and specialized features like high-end photography, video recording, and gaming. It also stands out as one of the few devices to feature S Pen support without being part of the Note series.