The BlackBerry Bold 4, widely known as the BlackBerry Bold 9900, is a classic smartphone released in August 2011. It features a 2.8-inch capacitive touchscreen (640×480 pixels), a physical QWERTY keyboard, an optical trackpad, a 1.2 GHz processor, and BlackBerry OS 7.

Key Specifications:
• Display: 2.8 inches TFT LCD, 640 x 480 pixels
• Keyboard: Full physical QWERTY keyboard with optical trackpad
• Processor: 1.2 GHz QC 8655
• Memory: 768 MB RAM, 8 GB internal storage (expandable up to 32 GB via microSD)
• Rear Camera: 5 MP with LED flash and 720p HD video recording
• Battery: Removable 1230 mAh Li-Ion
• Connectivity: 3G, Wi-Fi 802.11 b/g/n, Bluetooth 2.1, GPS, and NFC

Software and Legacy:
• Runs on BlackBerry OS 7.0 (upgradable to 7.1).
• Celebrated for having one of the best tactile physical keyboards ever engineered by BlackBerry.
• Core BlackBerry internet and network services for this OS version have been discontinued by BlackBerry, making it primarily a collector’s item or a nostalgia piece today.

The BlackBerry Z10 is a touchscreen smartphone launched in January 2013. It features a 4.2-inch display, a dual-core 1.5 GHz processor, 2GB of RAM, an 8-megapixel rear camera, and runs on the gesture-based BlackBerry 10 operating system

Key Specifications:
• Display: 4.2 inches, 1280 x 768 pixels (~355 ppi density)
• Processor: Dual-core 1.5 GHz
• Memory: 2GB RAM and 16GB internal storage (expandable via microSDXC)
• Cameras: 8 MP rear camera with 1080p video, 2 MP front camera
• Battery: Removable 1800 mAh battery
• Connectivity: 4G LTE, Wi-Fi 802.11 a/b/g/n, Bluetooth 4.0, NFC, and Micro HDMI

Software and Features:
• BlackBerry 10 OS: Introduced a fluid, gesture-based navigation system instead of physical buttons.
• BlackBerry Hub: A centralized inbox that aggregates emails, text messages, and social media notifications.
• Virtual Keyboard: An adaptive keyboard that learns your typing style and predicts words.