Continuity

the meaning of continuity

a detailed script used in making a film in order to avoid discontinuities from shot to shot

This makes filming easier and more accurate, so that the audience doesn't get confused if the character has moved. such as filming shot reverse shot, both takes from both side must be done the same to avoid any changes that the audience may notice.

http://www.google.co.uk/search?hl=en&safe=off&rlz=1R2GZAZ_enGB390&site=webhp&defl=en&q=define:continuity&sa=X&ei=jffOTMTuO82TjAfa3_TWBw&ved=0CBUQkAE

• The 180° rule is a basic guideline in film making that states that two characters (or other elements) in the same scene should always have the same left/right relationship to each other. If the camera passes over the imaginary axis connecting the two subjects, it is called crossing the line. ...
  this is used because if the camera were to break this rule, the audience could be confused as to which side the character is standing.

http://www.google.co.uk/search?hl=en&safe=off&rlz=1R2GZAZ_enGB390&site=webhp&q=define%3A180+degree+rule&meta=

• Shot reverse shot (or shot/countershot) is a film technique wherein one character is shown looking at another character (often off-screen), and then the other character is shown looking "back" at the first character. ... this is used so that the audience can see each character speaking and acting

http://www.google.co.uk/search?hl=en&safe=off&rlz=1R2GZAZ_enGB390&site=webhp&q=define%3Ashot+reverse+shot&meta=

either an action commenced in shot A is completed in shot B, or an action in shot A is mirrored by an action in shot B, for example when we cut from character A in location A reading a letter to character B in location B reading the same letter. this is create emphasis on the action or object rather than the character.

these are my examples of shot reverse shot

These are my illustrations for the 180 degree rule and shot reverse shot