What is the meaning of the "mark" in the original text of the Book of Revelation?

An English version of the relevant part of the Scripture is this: > "16 And he causeth all, both small and great, rich and poor, free and > bond, to receive a **mark** in their right hand, or in their foreheads: > > 17 And that no man might buy or sell, save he that had the mark, or > the name of the beast, or the number of his name." As far I know, it is a relative well cited part of the scripture today. The important question is, what is the word used for **mark** in the original, Greek text, and what did it mean? I think, we all can imagine, what it could mean. For example, if I use a pen to draw a circle on my hand, that will be a mark. But there was no pen at the time, and writing durable marks to human skin was not trivial at the time. I believe, this might be the reason, why is it interpreted as like a tattoo today. Because tattoo was known (and was forbidden since the early Old Testament era). But that is our current interpretation. What is the word used for "mark" in the original, Greek text, and exactly what did it mean, considering the culture and technological customs of the era?