T&L - Transform and Lighting, or separate engines on the graphics chip itself, that are used strictly for processing transform (vertex) and lighting effects. The benefit is that on games coded with hardware T&L in mind, the CPU has a lot of free cycles that would have usually been used for such processes.
Terabit - 2^40 bits, or 1,099,511,627,776 bits. Appreviated by "Tb" and generally it's referred to as "about a trillion bits" or "about a thousand gigabits". It is pretty rare to see this measurement used in most situations.
Terabyte - - 2^40 bytes, or 1,099,511,627,776 bytes. Often appreviated by "TB" and generally it's referred to as "about a trillion bytes" or "about a thousand gigabytes". A single terabyte can hold about 1,613 standard CDs or over 728,170 floppy disks. Big number, eh?
Somewhat interesting facts:
Yeah, it's pretty big number, and it is quite rare to see the monstrous "terabyte" in most situations, but with Internet file sharing programs where thousands of users share files, a "terabyte" is actually a rather small number, and is more likely replaced by several petabytes (1024 terabytes) and some day, an exabyte (1024 petabytes) will become standard. Many many years from now, perhaps a zettabyte (1024 exabytes) or a yottabyte (1024 zettabyte) will become a reality. One single yottabyte can hold the data of over 800,000 trillian floppy disks, over 1700 trillian CDs, over 130 trillian 2-layer DVD-9 (8.5 GB) disks, or 214 billion 200GB hard drives.
If you stacked the hard drives vertically, you could make 21 separate stacks that could each reach the moon, and still have enough drives left over to download everything off of Kazaa quite easily.
Texel - Stands for texture element. A single pixel applied to a bitmap in 3D. Or a pixel in a 3D world. (Similar to the difference between meteor and meteorite)
Texture - The graphical pattern applied to 3D polygon-mapped structures. The texture wraps itself around polygons and becomes stretched and skewed to give a 3D graphical effect. Textures paint the beautiful 3D world we see in everyday games, and without textures, games would be flat and lack detail (For example, remember Virtua Fighter).
Texture Compression - Video accelerator's ability to reduce image data size by replacing chronic strings and lowering the color palette of a texture. This technology can drastically increase framerate and available memory bandwidth by decreasing image quality, or increase visual quality by maintaining a constant palette.
Texture Mapping - The actual process of applying a texture or bitmap to a 3D polygon-mapped structure. Also known as texturing.
Texture Memory - A videocard's memory dedicated specifically to storing texture maps already fused with 3D objects.
TFT (Thin Film Transistor) - Ultra-thin monitors. More technically, the essential component in LCD or thin laptop monitors.
3D Positional Sound - Examples of 3D Positional Sound include Sensaura's 3D Positional Sound, Aureal3D, and DirectSound3D. This is a developer's ability to program sounds in 3D rather than just left or right channels (Stereo Sound). Complex mathematical algorithms make it all possible.
3DNow! Instructions - AMD's set of 21 instructions introducedwith its line of x86 based processors to increase floating-point (fractional) mathematical calculations. 3DNow! first appeared in AMD's K6-II and is also licensed by Cyrix and Centaur Technology. Generally, games that utilize the 3DNow! instructions run faster than those without.
Transparency - An object or material's ability to be seen through. Transparency effects in a game include simulated glass, water, smoke, explosions, and ice.
Trilinear Filtering - Process of applying bilinear filtering to either side of a texture causing extreme image smoothing and reducing noticeable pixelation. For a more in-depth definition, see this guide.
TruForm - ATI's process for creating smooth curves with few polygons is called TruForm. The process involves converting triangles to curves, in order to create a more smooth object, then turning them back to triangles so they can still be displayed and manipulated as triangles. This results in much smoother curves and rounded objects.
Tweak - Overclocking, cleaning, optimizing, and tinkering. Call it what you like. Nevertheless, the act of increasing system performance, customizing a PC, and bumping up efficiency, and the concept this site was built around.