There are some important terms to be remembered so I want to write it out here for my references and sharing. The information is gathered from the Internet, so it maybe right or it maybe wrong.
ISO = how sensitive your camera is to light. ISO 200 is twice as sensitive as ISO 100. ISO 400 is twice as sensitive to ISO 200. The more sensitive (higher ISO) the shorter the exposure needs to be for a similar image.
Exposure (shutter speed) = how long your shutter will stay open, allowing light to collect on the image sensor. 1:15 is 1/15 of a second. 1:4 is 1/4 of a second. Remember, in shutter speeds less than a second, the LARGER the bottom number, the SHORTER the exposure (provided that a 1 is the numerator) 6/10 is more than twice as long as 1/4. Also, camera shake can cause blurry photos at settings longer than 1/15.
Aperture: F-stops are different settings allowing different amounts of light to enter your camera. This is different from exposure, in that the aperture is that funky iris/anus looking thing that is a series of connected sheets that either open or contract to make a hole get bigger or smaller. If you watch the LCD on your camera and adjust the aperture, you will see which setting opens up the iris to allow more light in by watching your LCD become brighter or dimmer.