The term stained glass can refer to coloured glass as a material or to works created from it. Throughout its thousand-year history, the term has been applied almost exclusively to the windows of churches and other significant religious buildings. Although traditionally made in flat panels and used as windows, the creations of modern stained glass artists also include three-dimensional structures and sculpture. Modern vernacular usage has often extended the term "stained glass" to include domestic leadlight and objets d'art created from came glasswork exemplified in the famous lamps of Louis Comfort Tiffany.

As a material stained glass is glass that has been coloured by adding metallic salts during its manufacture. The coloured glass is crafted into stained glass windows in which small pieces of glass are arranged to form patterns or pictures, held together (traditionally) by strips of lead and supported by a rigid frame. Painted details and yellow stain are often used to enhance the design. The term stained glass is also applied to windows in which the colours have been painted onto the glass and then fused to the glass in a kiln.

The design of a window may be abstract or figurative; may incorporate narratives drawn from the Bible, history, or literature; may represent saints or patrons, or use symbolic motifs, in particular armorial. Windows within a building may be thematic, for example: within a church – episodes from the life of Christ; within a parliament building – shields of the constituencies; within a college hall – figures representing the arts and sciences; or within a home – flora, fauna, or landscape.

Stained glass is still popular today, but often referred to as art glass. It is prevalent in luxury homes, commercial buildings, and places of worship. Artists and companies are contracted to create beautiful art glass ranging from domes, windows, backsplashes, etc. 

Glass etching comprises the techniques of creating art on the surface of glass by applying acidic, caustic, or abrasive substances. Traditionally this is done after the glass is blown or cast, although mold-etching has replaced some forms of surface etching. The removal of minute amounts of glass causes the characteristic rough surface and translucent quality of frosted glass. 

Various techniques are used to achieve an etched surface in glass, whether for artistic effect, or simply to create a translucent surface. Glass etching cream is used by hobbyists as it is generally easier to use than acid. 

Abrasive blasting ("sandblasting") is another common technique for creating patterns in glassware, creating a "frosted" look to the glass. It is often used commercially. 

Glass fusing is the technique used to join glass pieces together by partly melting the glass at high temperature. The fusion process requires multiple pieces of glass. The heating is commonly undertaken in an electric kiln. Instead of fitting glass together using a lead solder, two or more pieces of glass are laid on top of or overlapped on each other and are fired.

It is important to realize that glasses with different coefficients of expansion or viscosity cannot be fused together. Upon cooling or after a period of time, the fused piece will crack.  Moulds can also be used in glass fusion, this is a process called slumping, glass is laid over the mould (generally made of ceramic or metal) and forms to it creating pieces such as plates and candle holders.

Beveled glass is usually made by taking thick glass and creating an angled surface cut (bevel) around the entire periphery. Bevels act as prisms in sunlight creating an interesting color diffraction which both highlights the glass work and provides a spectrum of colors which would ordinarily be absent in clear float glass.

Beveled glass can be obtained as clusters which are arranged to create a specific design. These can vary from simple three or four piece designs.

A mosaic is a piece of art or image made from the assembling of small pieces of colored glass, stone, or other materials. It is often used in decorative art or as interior decoration. Most mosaics are made of small, flat, roughly square, pieces of stone or glass of different colors, known as tesserae. Some, especially floor mosaics, are made of small rounded pieces of stone, and called "pebble mosaics".