What is the difference of DVRCam C901 from Normal CCTV camera?  
Normal cctv camera is a camera only, and must work with additional DVR device for video recording.  With DVRCam, you only need a Micro-Card (32GB).  The C901 is a Coomatec DVRCam Micro SD Card DVR CCTV Camera ;It special micro sd card dvr camera usded in long distance day and night view. You can check the night vision  of  Coomatec  C901 in YouTube.

DVRCam WR C901 specification

Video Camera Basics

Dimensions                 28*13*9cm

Gross Weight              820g

Power Adapter             Input: C 100~240V; Output: DC 12V, 2A

Micro processor           ARM9 32-bit microprocessor core

TF Card Support           Up to 32GB

Warranty                     Two-years parts

Video Camera Details
Type                           White

Digital Video Format     MPEG4/3gp;VGA (640 x480)  

Lens                           f=12mm

Field of View                45 degrees (diagonal)

Night Vision                 30-50m

Minimum illumination   0.1lux/f1.2

SNR                            48db

Operating Temperature -10°C~60°C