In some molding and machining operations, the pattern is a standard piece whose shape is copied to make additional pieces. For example, in sand casting of metal parts, the pattern is placed into a frame, sand is packed around it, the two parts of the sand mold are separated to remove the pattern, then the mold is reassembled and molten metal is poured in to create a new part that matches the pattern.
In software, a Template is a "partially completed unit of work".
In clerical applications, a Template is a "partially completed unit of work", or "a blank form", or it can also be an EXAMPLE of a completed unit of work.
In manufacturing, a Template and a Pattern are pieces to be copied, while a partially completed unit of work is often called "a blank".
In forming liquids (casting) a mold is the negative form used to shape the liquid solid while it sets.
In forming solids (forging or stamping) a mold is a negative form used to stamp the solid material into the final shape. This is also sometimes called "a pattern", and sometimes called "a stamp", and sometimes called "a press".
And there are regional and/or industry specific variations as well.