FAQ

There is no reason given within the show for why the Klingons look so different, and the producers of Discovery have stated they simply want to put their own stamp on the Star Trek universe. Hence why the look of the Klingons has been retconned.

This is not the first time the Klingons' appearance has changed within Star Trek. In the original show from the 1960s, the Klingons were very human looking. This was due to budget constraints at the time, but when Star Trek: The Motion Picture was made in 1979, the huge budget enabled the filmmakers to make the Klingons more alien and exotic with cranial ridges, sharp teeth and more hair. This look became the most well known among audiences and endured for over a quarter of a century in subsequent Trek films and the Star Trek shows The Next Generation, Deep Space Nine, Voyager, and Enterprise. The discrepancy between the look of the "human" Klingons of the original series and the more alien Klingons that came afterward was finally explained in an episode of Enterprise in 2005 and attributed to a virus that caused genetic mutations among some of the Klingon population. However, no explanation has been given in Discovery as to why the Klingons have changed again, (such as, they don't have any hair) and is one of many ways in which the show breaks with established canon.

No one has answered this question yet.

No, not really. But since it's a series set in a universe then the more you've watched the more you will understand about certain concepts and expectations the series sets forth.

Neither. It attempts to follow a lot of the prime timeline, but has many events that directly go against TOS, putting this in a 3rd timeline.

It´s not the USS Defiant from Deep Space Nine. It´s the Constitution-class USS Deviant from the original Star Trek (TOS) which vanished into a interdimensional rift while almost taking James Krik with her. She left the rift in the mirror universe and also in the past, enabling the Terran Empire to get their hands on techology which was 100 years more advanced than everything avaiable and therefore to conquer most of the quadrant -> see In a Mirror Darkly in the 4th season of Enterprise.

No. More than 100 years after Star Trek Enterprise and about 10 years before Captain Kirk took over the USS Enterprise.

The First Two Seasons of the series takes place approximately 10 years before Star Trek: The Original Series and is therefore set around the 2250s. In fact, in the pilot episode, an exact date of Sunday, May 11, 2256 is mentioned. Series creator Bryan Fuller has stated that the series takes place in the Prime Universe (in which The Original Series, The Next Generation, Deep Space Nine, Voyager, Enterprise, and the first ten feature films take place, and not the so-called "Kelvin Universe" in which Star Trek (2009), Star Trek Into Darkness and Star Trek Beyond all take place). Starting with Season Three, the series takes place some 900 years later. So, technically, Discovery is the furthest along in the time line that any Trek series has been set in.