A Video Capture Card is a PCB that fits inside a PC to allow it to take analogue video signals and convert them into a digital signal for viewing on a PC. These can sometimes include TV and Radio tuners too. Most often the term Video Capture Card infers a single channel video input with TV or Radio too.
The abreviation DVR stands for Digital Video Recorder. Typically a DVR card has a minimum of 4 analogue video inputs and may have as many as 16 on one card. DVR cards are usually used for Security and other such applications where you need multiple video signals to be recorded e.g. in a security CCTV system.
The software for DVR cards ranges in complexity but usually even the most basic DVR card software includes recording to hard disk, Movement Detection and alarms. Some of the more complex software has many advanced features including remote access over the Internet and by mobile phone, highly sophisticated search operations for the easy location and retrieval of recorded images and events and linking to third party applications and devices to form a complete CCTV management system.