Agreed with what was mentioned above, but want to add that the current trend is toward "all day" bikes.

Ultralightweight XC bikes sacrifice durability, FR bikes sacrifice weight, DH bikes are so specific, they sacrifice everything besides going fast in the downward direction.

The compromise between all has become the "Trail" bike. The broad description is a full suspension bike with 4 to 5 inches of suspension travel front and rear. Disc brakes, comfortable riding position and approximate weight of 27 to 32 lbs, depending on your budget and weight/durability concerns.

Tires have become a little wider as technology increases. i.e. tubeless tires can be run with lower air pressures for more traction without sacrificing pinch flat susceptability. Also, the rubber durometer (stiffness rating of rubber) has become heavily researched and tires provide better grip, durability and/or weight.

I think in the last 5 years suspension designs have stabilized. There are two or three basic designs with only slight variations of each. However, the suspension technology has increased. Meaning the shocks/forks have become much better with many more tuning options and "smart" suspension that only activates from bump input, not rider input. So, you have a full suspension bike that responds like a hardtail when hammering out of the saddle.

Bikes like the Specialized Enduro, Turner 5 Spot, K2 Lithium, Yeti ASR, Intense 5.5 XVP, Santa Cruz Blur.....etc.

L8R