In truth, the original Snitch was a bird named the Golden Snidget, not a golden ball. Witches and wizards alike would scurry around in search of the Golden Snidget, anxious to claim the reward of 150 galleons for whoever captured the bird. For many years, the Golden Snidget was an element of the game. However, after its death, no one knew how to play without a Snidget, so the Ministry of Magic made an agreement with Hagrid to keep his giant Growling Crocodile as a replacement.
The game of Quidditch is based on chukkon-skull-ball, a game that has been played in Hogwarts' courtyard since it was built. The term "snitch" comes from the British English slang word "cheat." In ancient Greek games, a snitch was a small bird used by trainers to signal when their athletes were out of shape or tired during long competitions.
So the snitch was basically a tiny bird used to tell players when they are being watched/checked up on? That makes sense because that would be useful in a game like quidditch where you can't see everything that's going on.
Here is how the Ministry of Magic defines a snitch: "A snitch is a small bird used by trained birds to indicate which players are 'out of shape' or 'tired.'".
The Golden Snitch is a magical golden ball used by Quidditch players as an offensive and defensive weapon. When thrown, the Snitch will locate the most opportune moment to strike down its target.
It is this quality that makes the Snitch such a potent weapon for its owner. One look at the Snitch and you know whether or not it is going to be caught by one of the three Chasers participating in the game. If it is caught, the player who caught it can do anything he or she wants with it. However, if it isn't caught, the player loses his or her life because he or she is unable to release the Snitch before it hits the ground.
In addition to being useful in Quidditch games, the Snitch is also capable of uniting people who have been separated by time, death, or distance. In fact, several characters in the Harry Potter books were able to communicate through visions by looking into their eyes. Once the victim looks into the other person's eye, he or she will see his or her image reflected back at them.
Harry Potter catches a Golden Snitch in the first book by eating it during his first Quidditch match. Potter later learns that Dumbledore concealed the resurrection stone within that snitch. Dumbledore's will leaves the resurrection stone-containing snitch to Harry after his death. Harry finds the snitch in his bed when he returns home from the hospital after the murder of Dumbledore.
He opened it using the Resurrection Stone inside, which was given to him by Voldemort at some point before their fight on the graveyard floor. After doing so, Dumbledore raised himself up with his arms outstretched as if welcoming Harry back from the dead.
Snitches tell lies. That is what Snape tells us right from the start of Harry Potter and the Sorcerer's Stone. Indeed, a snitch has already lied to Harry once before he eats the snitch at the Quidditch game. When Snape sees that Harry is about to eat the snitch, he pretends it isn't real and throws it away. As soon as Harry takes a bite of the snitch, however, it begins to emit a loud noise that alerts everyone at the game that something strange is happening. Even though Harry doesn't realize it yet, the snitch is telling the truth this time!
If you read the book or see the movie, you will know how Dumbledore dies at the end.
Dumbledore had set a spell on the Snitch that would be disclosed only when Harry placed it in his mouth and experienced self-acceptance. Harry remarked, "I am going to die," after inserting the Golden Snitch in his mouth, and the Snitch opened. The spell then told Harry what choice he had made, and how it affected him.
Harry heard the words "You have chosen love." He then woke up in his bed at Hogwarts School of Witchcraft and Wizardry with the Golden Snitch in his hand.
Dumbledore had used this same spell on Cedric Diggory when he saved Harry's life during the Deathly Hallows trial. It was revealed later in the book that Cedric had also said those same words when he chose to sacrifice himself to save Harry from Voldemort's curse.
This scene shows that love is more powerful than death. Even if you choose to love others enough to give your life for them, they still can't know unless you tell them. The only way to show them is by saying the words "I love you" first.
Also, Dumbledore proved that there is a way to reveal any secret you want to someone else. In order for this spell to work, both parties have to accept themselves completely before doing so.