color: color should support the message of whatever it is displayed on as it can emphasize a point or convey a message.color is the act of an object reflecting a certain light back to your eye.
Balance is when the contents of the page is spread out evenly. Balance can be used to create unity and can also be used to emphasize a certain part of the art.
a line is a path of some kind that your eyes follow, it can be used to lead you through an image.
texture is the way things feel but in photography as you can not touch the image you can get a feeling of how this thing really feels to touch.
shape is one of the things that define objects in space, they are 2 dimensional and are generally created by lines.
value describes the brightness or darkness of an object
form is making an image look 3 dimensional even though it is 2 dimensional
space is a feeling of depth or 3 dimensions but can also mean the use of area
contrast draws your eye without you really noticing that you're drawn there, you can contrast images, ideas and colours
alignment is aligning multiple things so they fit together, there is edge and center alignment
repetition is repeating something over and over to make it interesting or create a pattern
proximity is how close things are to each other, it can also be how close to the subject the photo is taken.