What is a digital signautre?

Is their a way you can zoom in pictures from a site? When did the digital take over happen? Where can one find a guide to installing a CCTV camera dome onto a wall? Fuji a850 camera only clicks will not turn on? What is The structure that regulates the size of the opening for light in and is similar to a camera diaphragm? Why does your camera turn off every time you put your SD card in? What did people do before cars were invented? Where can one purchase a CCTV security system? What is the difference between traditional photography and digital photography? Are there different types of optical features and which is the most recommended when purchasing a camcorder.? Which are the best digital cameras for taking close up photographs? Is there cctv everywhere? Is the Lorex LW 2932 a 9 inch monitor an IP Camera system? Does the Sony Alpha 100 DSLR camera have live view? What brands make the most reliable point to shoot cameras? Does flash flood really waterproof phones? What was one of the earliest platforms used to take aerial photos? How do you use the self timer on the asahi pentax k1000? What is the answer to The 39 Clues card 1 surrveillance camera? Who are the canonites?