Specifications:

OS: Android 8.0 (Oreo)
Display: Galaxy S9: 5.8" Galaxy S9+: 6.2"
Camera: Rear: SuperSpeed Dual Pixel 12MP AF Front: 8MP AF
Speakers: Stereo speakers tuned by AKG, Dolby Atmos surround sound.
Memory: Galaxy S9 4GB RAM 64GB Galaxy S9+ 6GB RAM 64GB
Battery: S9 3000mAh S9+ 3500mAh

Features:

Fast Charging on wired and wireless
Intelligent scan: Combines iris scan and face recognition for convenient unlocking and in some cases provides enhanced security for certain authentication services.
Bixby - Vision: AR Experiences for Translation, Shopping, Place, Food, and Image.
Edge Panels: Apps edge, People edge, Smart select, Reminder, Tasks edge, Quick panel, Clipboard edge, Device Maintenance, Weather, Calendar.
Live focus with bokeh filters (background blur effect)
4K video recording at 30 fps or 60fps
Water Resistance IP68
and many more..

#Colors:

Midnight Black, Lilac Purple, Coral Blue and Titanium Gray

Price:

A new Galaxy S9 starts at $720, while the Galaxy S9 Plus starts at $840.
In India, (MOP) starts at Rs. 57,900 for the 64GB model, and goes up to Rs. 65,900 for the 256GB variant. The Galaxy S9+ price in India starts at Rs. 64,900 for the 64GB model and goes up to Rs. 72,900 for the 256GB variant.