What does it mean to be stationary? I'm looking for a simple answer. What do we regard a stationary. Do we mean an object that is not moving noticeable from the viewers perspective because then a parked car would be considered stationary, but (assuming it's on earth) the earth is rotating and those at the circumference where the spin is greatest are traveling 1 038 mph and the earth itself is moving with the Milkyway at 600 000 mph. I have a bunch of other questions but I rather not put them all in one post, but do we really account for theses other speeds or do we ignore them.
 A: This term is used all the time in introductory classical physics. In that context, stationary usually means not moving in the laboratory frame. Thus, a block sitting on a table not doing much would be referred to as being stationary.
If one studies relative motion, then stationary could mean not moving in whatever frame you're discussing.
A: A simple answer:  motion is relative thus, there is always an implied reference.  In other words, if you read or hear the phrase "X is stationary", you should immediately think "stationary with respect to what?". 
Most often, it is the case that an unqualified "stationary" means "at rest with respect to the measuring apparatus" or "with respect to the lab".  But, of course, the apparatus or lab is not an absolute reference and thus, the lab is relatively moving with respect to ... a lot of other things.
In fact, all we can really say is that two or more objects are moving relative to one another or not; there is no absolute rest with which to say that something is absolutely stationary or moving.
