BG - Background
Blending - How well the render matches the BG and how each resource is used.
Blurred - Self explanatory
Brushes - Used for adding effects and creating a background. Mainly used for abstract pieces and smudging.
C4D - A resource created in Cinema 4d. It is used for creating effects and blending. You have both abstract and effect c4ds.
Classing - Placing an artist on a certain level of art depending upon their artistic abilities.
CnC - Comments and criticism. Thoughts/opinions given by someone pertaining to a piece of art.
Composition - Basicially how everything shown in the piece works together. For example, how well the c4ds or resources blends the focal in.
Concept - The main idea/inspiration behind the artist's work.
Contrast - The difference of brightness between dark and light colors. (making darker colors darker while bright colors brighter)
Depth - Simply making your focal be the one thing that the viewers look at first. The blur tool is one of the most essential tools used for creating depth.
Depth of field (DOF) - Where a part of a render is sharper than the rest making it look as if that part is reaching out to you.
Destructible Edits - Changes that you can make to stock or photo that change it permanently.
FG - Foreground
Flow - The overall direction of effect and tag.
Floating Head Syndrom(FHS) - When the body of the focal is overblended and the head is the only part that is seen.
Fractal - Similar to effect c4ds but are made in Apophysis rather than Cinema4d. The layer modes for effect c4ds can be applied to fractals and still look great.
Full Rights - Rights to distribution, learning and editing. With full rights, you get to edit the psd/xcf as if you made it.
Gradient Map - An adjustment layer with one or two colors used for adjusting your art's color.
HQ- High quality
Illustrator shape - A render made in Illustrator that resembes a shape or vector appearance. Unique way for blending.
Lighting - Where the light comes from and creates shadows.
LP- Large Piece
Learning Rights(LR) - Rights to only learning the concept, skillz and techniques shown in the psd/xcf.
LQ- Low quality
Masks - Cut out of an image, like a render but non-destructible.
Non-Destructible Edits - Changes made to a stock or photo that can be easily removed.
Opacity - How transparent a certain layer or object is.
Pixelated - When the pixels of a stock, photo or piece of art are visible to the naked eye.
Posting Rights(PR) - Rights to distribution in resource packs as well learning rights to the psd/xcf.
Render - An image that is rendered from a stock or photo.
Rendering - The process of rendering an image out of a stock or photo.
Render(3d)- Final image projection of 3d artwork.
Ripping - Ediing someone artwork without permission or full rights to it.
Rule of Thirds - The idea that all images can be cut in to 9 squares. (helps with text placement)
Stock - A basic image. Used for backgrounds or tags that are mainly stock.
Text - Pretty self explanitory.
Textures - Used for adding effects, and sense of feel to the art.
Tone - The lightness/darkness of a color.
Topaz - Photoshop addon that allows you to filter out the LQ appearances that stock, images and finished versions art might have.
Using Right(UR) - Rights to wearing it in your sigspace.
Vector- A very high quality revision of a stock or photo at high resolutions. Basically you recreate the image using pen tool in Photoshop or using shapes in Illustrator.
Vector(alternative) - A piece solely made from shapes using big canvas's and high resolutions. (Usually done in Illustrator)
Vexel - A piece solely made from shapes. Similar to Vector in illustrator but Vexel's are made in photoshop.
WIP - Work in progress.
Whored resources - Resources that have been overused, and/or widely distributed.
Credits to Ignis from PD. This was originally his post XD