The easiest way to define a sports saber. Her guard is oval with a bracket that protects the fingers during a chopping blow. The blade of the saber is trapezoidal. The sword and rapier have a round guard, but the sword has a three-sided blade, and the rapier has a four-sided one. In addition, the epee is heavier: the weight of the epee is up to 770 g, and the rapier is 500 g.
You can't see anything, he doesn't show the blade in close-up, they all look the same. And he hardly shows how to use it either.
I had to show 3 fights - a saber with a sword, a saber with a rapier, and a rapier with a sword.
I suppose, for comparison, the author of this question will be curious and look not sporty, but traditional, as it was in history:
At one of the historical moments in duels began to prohibit the use of swords, and switched to sabers, because stabbing wounds have a higher mortality rate than cutting wounds.
First, what is a sword. Comes from the Spanish word Spada - sword and in this sense there is some confusion in terminology. For this, now we will consider sports equipment and historical ones.
A sports epee is a three-edged blade designed exclusively for thrusting into any part of the body and the thrust must be quite strong - 750 newtons for the light bulb to light up.
Before the revolution it was called a sword the actual military civilian weapon. And the training one was called a rapier, that is, a lightweight sword. I will show an example with the historical hilt of the rapier blade. It is tetrahedral and only gets into the body. A training projectile, which over time has grown into a separate sports discipline.
And finally, a triangular saber blade with a pronounced chopping edge, in order to cut first of all, it is stabbed with it, but rarely with a kind of guard. It would seem that this could have ended, but no. Because the historical saber has a completely different potential, completely different weight and size characteristics and is a rather inertial weapon.
And the rapier looked like this, and that was exactly the main shell of the Renaissance. A well-developed guard, a very long blade allowed chopping blows, but first of all stabbing. And this was called a rapier, a civilian weapon with which, in general, they fenced in all the later Middle Ages, especially during the Renaissance. And this difference is very consonant in one and the other language introduces some confusion.
I hope I was able to help you figure it out. Be healthy. Fencing in the 21st century and before communication.