Why is the understanding of the term 'anachronistic' fundamental to studying Shakespeare ?
An anachronism is a moment when a scene is chronologically out of place. This is really important in Shakespeare because quite often, because you can't be in two places at once, he will show scenes one after the other. We as audience members have to understand that these two scenes actually occured at the same time.
In Romeo and Juliet for example, the Nurse and Romeo are talking, likely while Juliet is wondering where the Nurse is. Shakespeare later brings the Nurse into Juliet's scene, but it takes some time.
Some of his plays take place over a longer amount of time, but Romeo and Juliet is just a few quick days. He has to show scenes that must be happening at the same time in order to reveal the details necessary for us to understand the conflicts of the story taking place. It's not like a movie that can show a split screen.
Good answer. Anachronistic also means out of time and place in a bigger sense--as in a knight riding a white horse is not something we'd see today. It's anachronistic. I'd add the idea that part of studying Shakespeare and his works is looking at how directors over the years have treated his works. Many of them are hugely anachronistic--setting his sixteenth-century works in a modern, or even futuristic, world. These changes, including sometimes "modernizing" the language, are worth studying in order to see how the basic themes and characters of Shakespeare hold up today. The text matters most, but how others treat the text is also worth observing.