The Apple iMac Retina 4K 21.5-inch All-in-One Computer is an extraordinary blend of technology and design, making it a perfect choice for both professionals and casual users alike. With its sleek, seamless aluminum enclosure, this iMac not only performs remarkably but also looks stunning in any setting.

Equipped with a powerful Intel Core i5-5675R Quad-Core processor running at 3.1GHz, this computer can handle demanding tasks with ease. The maximum turbo frequency of 3.60GHz ensures that you have the power you need when you need it most. The 4MB SmartCache enhances the efficiency of your workflows, allowing for smooth multitasking and rapid access to frequently used applications.

One of the standout features of this iMac is its breathtaking 21.5-inch Retina 4K display. With a resolution of 4096×2304, images and videos appear incredibly sharp and vibrant. The IPS technology ensures wide viewing angles and consistent colors, making it an ideal display for graphic design, photo editing, and media consumption. The display runs in a pixel-doubled mode to provide a beautiful 2048×1152 appearance, which means every detail is crystal clear.

The iMac also comes with 8GB of onboard 1867 MHz LPDDR3 RAM, which is sufficient for most tasks and can be upgraded to 16GB at the time of purchase. However, it’s important to note that this RAM cannot be upgraded after the initial purchase, so it is advisable to consider your future needs carefully.

For storage, the iMac features a spacious 1TB hard drive, providing ample space for your documents, photos, videos, and applications. The built-in Intel Iris Pro 6200 graphics processor ensures that you will enjoy smooth video playback and decent graphics performance for casual gaming and creative tasks.

Connectivity options are abundant with this iMac. It supports WiFi and Bluetooth, allowing for easy connection to the internet and other devices. The built-in FaceTime HD camera and microphone enable you to conduct video calls with friends and colleagues seamlessly.

Running on Mac OS X El Capitan 10.11, the iMac offers a stable and user-friendly operating system. This OS is designed to enhance your productivity and creativity with features that let you work more efficiently.

In summary, the Apple iMac Retina 4K 21.5-inch All-in-One Computer is a remarkable device that combines high-performance hardware with stunning visual capabilities. Whether you are a creative professional, a student, or simply someone who enjoys high-quality computing, this iMac is sure to exceed your expectations.