output
The sound card of a computer provides an output - speaker or headphone) and usually an input too - microphone.The card itself is not an output but is an I/O device(input output device) [a bit of semantics here].
If you do not have a graphics card, you will be unable to receive visual output from the computer.
A TV tuner card is an input card that allows computer to receive television signals (digital or analog). A video card a.k.a. graphics card is an output card that allows to generate and output images to a display. source: Wikipedia
no
INPUT
You can buy USB network card, it will solve your problem.
I expect you mean "Is Card reader/writer input or output?". If this is so, it is both an input and output device. Whenever you are trying to categorize a device as Input or Output, think of how it looks from the computer.If the computer is transmitting data to it, it is an Output device.If the computer is receiving data from it, it is an Input device.
The Card that translate images to your monitor AKA a graphics card
To capture HDMI output in high definition (HD), you can use a capture card or a video capture device that supports HDMI input. Connect the HDMI output from your device to the capture card, then connect the capture card to your computer. Use recording software on your computer to capture the HD video output from the HDMI source.
The video card, or the motherboards onboard video output.
A video card is part of the output chain but is not an output device on it's own. The monitor is usually the device that is considered an "output device".