Affiliate program : An internal scheme within a microstock agency which allows users to earn credits through referrals to new contributers or buyers

API : Application programming interface; a communication platform implemented by a software program which enables it to interact with other software.

Artifacting : Any undesired alteration in digital data introduced during a digital process e.g post processing of an image. one type of artifacting is compression artifacting which result from aggressive data compression. The image discards some data that may be too complex to store in the available data-rate and results in digital distortion.

Bit depth : It quantifies how many unique colors are available in an image’s color palette in terms of the number of 0′s and 1′s, or “bits,” which are used to specify each color.

Chromatic Aberration : It is a type of distortion when a lens fails to focus all colors to the same convergence point. It occurs because lenses have a different refractive index for different wavelengths of light (the dispersion of the lens). Chromatic aberration manifests itself as “fringes” of color along boundaries that separate dark and bright parts of the image, because each color in the optical spectrum cannot be focused at a single common point on the optical axis.

IPTC : It is a type of metadata format. See metadata. It is the standard developed in the 1970′s by the International Press Telecommunications Council for exchanging information between news organizations.

Lightbox : Traditionally, it is a back-lit frame of clear plastic or glass to transmit light and aid the viewing of negatives or slides. In the digital world, it refers to a virtual collection of images (usually within a stock agency). A user can create a virtual collection of images from more than one photographer; lightboxes generally can be made private or shared publicly.

ND Filter : Neutral density filter; a colorless (clear) or grey filter which reduces and/or modifies intensity of all wavelengths or colors of light equally, giving no changes in hue of color rendition. ND filters allows the photographer greater flexibility to change the aperture, exposure time and/or blur of subject in different situations and atmospheric conditions.

Macrostock : Generally higher priced royalty managed licensed of images

Metadata : Electronically archived data. Image metadata can include image information such as camera make, lens type, shutter speed, aperture reading, owner information and much more.

Microstock : Low priced royalty free licensed images

Posterisation : It is a visual alteration of an image when it’s apparent bit depth (see Bit depth) has been decreased drastically. Posterisation occurs more easily in regions of gradual color transitions meaning these regions require more colors levels to describe them and so any decrease in levels can have a visual impact on the image.

RM : Royalty managed; a type of license. Content is licensed under a specific set of guidelines (usage, duration, print run, territory, size, industry, exclusivity) and can only use it within the contract specified guidelines.

RPI : Return per image; a portfolio performance indicator. RPI is calculated by taking your monthly earnings and dividing by the number of images in your portfolio. It indicates the performance of your portfolio relative to your own portfolio over time.

RF : Royalty free; a type of license. Once the content is licensed under a generic set of guidelines, the licensee is normally free to use it in perpetuity without paying additional royalty charges.

Scrim : Scrims are translucent diffusion panels placed in front of a light source to soften the light. Scrims are usually attached to a frame support.

TFCD : Time for CD; usually refers to a collaboration between a photographer and the model. Basis of exchange is determined between parties involved and usually do not involve monetary compensation.

TFP : Time for Photo/Print; usually refers to a collaboration between a photographer and the model. Basis of exchange is determined between parties involved and usually do not involve monetary compensation.

Upsampling : It refers to a process where a digital image is scaled upwards by creating pixel information based on the adjacent values, thus increasing the megapixel count of an image.

URL : Uniform resource locator; it is the address of a web page on the world wide web