Transition

Usually considered to begin when the person starts making changes with the intent of altering their appearance to more accurately reflect who they want to be. This may be something as simple as a change in hairstyle, or more radical, depending on the person.

When this period is considered to have ended varies from person to person, but is generally the point where there really isn't anything much left to change (at least to the people they see on a regular basis). However, it is, to almost everyone, definitely over by the time of sex reassignment surgery. There are a few people who would say that they consider transition to be a never ending process, but those people are in the minority.

In video work, a transition is a effect that is usually used in the beginning, end or the change of a scene. Without the transitions, the scenes would just change instantly, and sometimes this is not desired, because it doesn't fit that well to the scene. These are usually used to make it clearer that the next scene is taking place in different place or at different time.

Typical and very common transitions include

Fade out, fade in

Gradual complete tone change to/from black, or (rarely) to some other color. Often, a scene ends in fade out, and next scene begins with a fade in. On audio side, the fades are often used similarly; sound fades out, and then fades in.

crossfade

The previous scene fades away, and next scene fades into the view at the same time - and soundtrack is also mixed together, or may fade just like in fade out/in to black.

wipe/sweep

The old scene is replaced gradually with the new scene, or the picture is gradually blackened and the new scene is revealed similarly gradually; the scene is "swept" away. Usually sweeps run from one side to another in diagonal or straight angle, but there are other kinds of sweeps - shrinking or growing circles, stars, hearts; clock-like sweeps, spirals, 3D sweeps (e.g. picture flips over, new scene on the backside) and so on...

push/slide

Like sweep, but the old picture itself moves away and reveals the new scene (while in sweep both scenes stay relatively on same place).

Most NLE video programs handle transitions like this with ease.

In case of film, the transitions can likewise be done digitally, using different kinds of exposure to produce a copy of the negative, or physically by adding transparent tape on top of the film. There are other methods; For example, in ancient days, fades to black could be done by gradually dissolving the film emulsion from copy of the negative using some kind of dissolvant (acid?).

Thanks to QXZ for alternate terminology.

Tran*si"tion (?), n. [L. transitio: cf. F. transition. See Transient.]

1.

Passage from one place or state to another; charge; as, the transition of the weather from hot to cold.

There is no death, what seems so is transition. Longfellow.

2. Mus.

A direct or indirect passing from one key to another; a modulation.

3. Rhet.

A passing from one subject to another.

[He] with transition sweet, new speech resumes. Milton.

4. Biol.

Change from one form to another.

⇒ This word is sometimes pronounced tran*sish"un; but according to Walker, Smart, and most other authorities, the customary and preferable pronunciation is tran*sizh"un, although this latter mode violates analogy. Other authorities say tran*zish"un.

Transition rocks Geol., a term formerly applied to the lowest uncrystalline stratified rocks (graywacke) supposed to contain no fossils, and so called because thought to have been formed when the earth was passing from an uninhabitable to a habitable state.

© Webster 1913.