Emacs Power Usage

point, mark, region:

Many emacs operations can be preformed on regions, every buffer has a region defined
which is a section of the buffer. The region is defined by to coordinates:
point and mark. point is the current cursor position, and mark is a special pointer which
we place wherever we like.
We can place it explicitly at point, using C-space.
or we can use one of many alternate methods for marking a region.
such as: M-space which marks the current paragraph by placing mark at the end of the
paragraph and point at the beginning.
The region is usually not visiable, it is visiable only when mark is active and transient-mark-mode
is enabled. All commands that are meant for marking a region also activate mark, mark is deactivated
automaticly. Commands working on a region will normally not work when mark is not active, this
however is controlled by the variable: mark-even-if-inactive.
when using the mouse region is highlighted regardless of transient-mark-mode.
Meir Maor