What Does "Otsukaresama Desu" Really Mean?

This is one of the most versatile but mysterious words you will find in Japan, and a word that is used every single day.
What does "Otsukaresama desu" really mean, though, and how can I use it properly? I'd like to attempt to explain the use of this phrase, shed some light on how it is used and what the different meanings are.
In the work-place: Otsukaresama desu is most often used in work places and loosely translated it's a simple greeting that means that you acknowledge a fellow worker or person who is within in the same working environment.
A more direct translation might mean "you must be tired" however this is only used when the person you are saying it to has obviously tired themselves to do some work that has directly helped you.
In these cases, it may be more appropriate to say thank you, or in Japanese "arigatou gozaimasu" Strictly speaking Ostsukaresama desu is used to show appreciation for hard work, but in reality the usage is really broad.
It is most commonly used and easy to understand when fellow workers use the phrase at the end of a working day.
In a way it endears camaraderie between people and the spirit of team-work amongst people.
In many casual settings it is just like saying "hi" or "how are you?" or "how's it going?" or whatever you use as a greeting when you walk by someone in the hall.
Strangely enough, people don't use the "ogenki desu ka" phrase, meaning "how are you?" nearly as much as we do.
It is used more to really ask about someone's health and well being rather than a generic greeting.
However, the phrase can be found in a myriad of different situations where there seems to be little or no implied acknowledgement or appreciation of work taken place.
It's merely a simple way of starting or ending a conversation between working people.
Outside the work place.
In fact, you could use it outside the work place with people who you are familiar with, that you know are fellow working people, as a general greeting when beginning or ending interactions.
In these occasions it does not hold the same connotations as the above explanation and doesn't necessarily mean that you are trying to show any appreciation of their work.
I suppose it is like English speakers when we ask "How are you?" but care little about the answer, as it is merely a way of greeting someone or beginning a conversation.
Shorter versions of the phrase include "otsukare" among others.
The Japanese seem to love abbreviations of various words and this is no exception.
Japanese doesn't have to be as complicated as you think it is.
Japanese people can be very forgiving of foreigners and you do not need to understand all the subtleties.
Sometimes, in fact ignorance is bliss.
There are plenty of ways of learning Japanese online too!