Why do black holes have stronger gravity than their original star

i'm doing a report on black holes and i don't understand why they have a stronger gravitational pull then the star that it came from, the mass doesn't change. i know that the density does though. does density have anything to do with gravitational pull?

Black holes have exactly the same gravity as a star of the same mass does. This is a consequence of the fact that they DO have the same mass. Therefore, as long as you stay as far away from the center of the black hole as you do from the center of the star (that is, you don't go INTO the star), then you'll not be able to tell the two apart on account of gravity or tidal forces.

If you were to journey into the star, the mass above you and below you would begin to balance, and come to a balance when you reach the center. You would be weightless there.

Where black holes get their huge reputation for eating things is from the fact that they are much smaller in size than any star is. A black hole of the mass of the sun will have a diameter of about 4 miles, so you can get a lot closer to it than you can the sun. In that area of space, gravity continues to mount mercilessly, and at a distance of 2 miles from the black hole (which is a point with no size) you will enter the event horizon, that dread volume from which no light can escape. You're a goner at that point. A little closer in the tidal forces (a form of gravity) will begin to spaghettify you, breaking you into smaller and smaller pieces such that by the time you get close to the black hole you will be a spray of separated atoms.

The density of a black hole is infinite at the singularity. That makes the gravitational gradient there also infinite, so they are related. It is the density of the singularity that makes the black hole.

The mass id the same, but it is in a tiny space, therefore, the gravity at the black hole is "Super Concentrated". The formula for Gravity has the distance from its center squared, so if a star with a radius of 500,000 miles shrinks down to something only 50 miles in radius, and you weighed 1 Lbs on its surface before it shrank, you would weigh not 10,000 lbs on the new size star, but 10,000² lbs or 100,000,000 lbs. And this is for a 50 mile radius, it theoretically shrinks down to the size of an atom, so there is not enough space on your computer screen to put all the zeros after the 1 you would weigh if you could reach that spot. Hope that makes sense.