The workforce or labour force is a concept referring to the pool of human beings either in employment or in unemployment. It is generally used to describe those working for a single company or industry, but can also apply to a geographic region like a city, state, or country. Within a company, its value can be labelled as its "Workforce in Place". The workforce of a country includes both the employed and the unemployed (labour force). A bricklayer, which is related to but different from a mason, is a craftsman and tradesman who lays bricks to construct brickwork. The terms also refer to personnel who use blocks to construct blockwork walls and other forms of masonry. In British and Australian English, a bricklayer is colloquially known as a "brickie". A stone mason is one who lays any combination of stones, cinder blocks, and bricks in construction of building walls and other works. Bricklaying is a part of masonry.
Chroma key compositing, or chroma keying, is a special effects / post-production technique for compositing (layering) two images or video streams together based on color hues (chroma range). The technique has been used heavily in many fields to remove a background from the subject of a photo or video – particularly the newscasting, motion picture and videogame industries. A color range in the foreground footage is made transparent, allowing separately filmed background footage or a static image to be inserted into the scene. The chroma keying technique is commonly used in video production and post-production. This technique is also referred to as color keying, colour-separation overlay (CSO; primarily by the BBC), or by various terms for specific color-related variants such as green screen, and blue screen – chroma keying can be done with backgrounds of any color that are uniform and distinct, but green and blue backgrounds are more commonly used because they differ most distinctly in hue from most human skin colors. No part of the subject being filmed or photographed may duplicate the color used as the backing.