thanks muno

As Jamie said, a frame in smash is 1/60 of a second. For good frame data comparisons, you can check out http://kuroganehammer.com/Smash4. Here's an explanation of each column in a character page from that site:

Hitbox Active = the frame window during which the attack can connect. For Mario's dtilt, the Active Frames are 5-7. This means that there are four frames of Startup Lag, during which the attack cannot connect, followed by three Active Frames, during which it can connect.

FAF = First Actionable Frame = the frame starting at which you can act out of the move. It's pretty much the end of the ending lag. Using Mario dtilt again as an example, its FAF is 28. So on the 27th frame you're stuck in the animation, but once it hits frame 28, you can act. In SSB4 and Brawl, due to Buffering, actions input within a 10-frame window before FAF will be carried out right when the FAF begins. (https://www.ssbwiki.com/Buffer for details)

FAF is also referred to as IASA, or Interruptible As Soon As. Since the move is interruptible as soon as frame 28.

Base Dmg. = Base Damage = the damage the move deals before any multipliers. Factors such as staling can affect how much it actually deals in practice. By the way, each unique hit of a move is listed as a separate "attack" – for Mario, the early and late hit of his dash attack have different entries – and the same thing goes with angled ftilts / fsmashes that differ in properties.

Angle = the angle of the attack's knockback. The main thing to note here is that 361 is the Sakurai Angle, which sends a grounded opponent sliding backward at low percents and sends them diagonally upward at high percents. It's commonly used on moves intended for CQC, such as Mario's first two jabs, ftilt, fsmash, nair, and bair.

BKB = Base Knockback = the beginning value for a move's knockback, before factoring in things such as percent or weight. If a move has high Base Knockback, it launches the opponent far at low percents, as well as an increase in knockback at later percents if all other factors are the same.

WBKB = Weight-Based Knockback = basically set knockback. This knockback doesn't scale with percent, but as the name implies, does vary based on the opponent's weight. Some moves launch the opponent a set distance using this attribute, while others – such as Mario's first two jabs, all but the final hit of dair, and all but the final hit of Super Jump Punch – use it to keep the opponent from getting launched too far during a multi-hit move.

KBG = Knockback Growth = how much the knockback scales depending on the opponent's percent. A move with high Knockback Growth (a.k.a. Knockback Scaling / KBS) sees a bigger increase in knockback when an opponent has more damage. With low Base Knockback but higher Knockback Growth, a move could be made to keep the foe close at low percents to start a combo while KOing at higher percents.