In short, the meaning of the Battle of Waterloo for Napoleon and France was the end of the Napoleonic era. Here is an explanatory summary:
After being proclaimed emperor, Napoleon began his plan of expansion, whose main objective was to dominate the whole Old Continent. But the achievements were not so easy, so much so that it even won an official name "The Napoleonic Wars". Whenever he emerged victorious, Emperor Napoleon appointed friends and family to lead our territories. In 1812, his power began to crumble. Thanks to the Russian intervention that did not yield to the French army. A year later, Napoleon lost his throne and had to exile on the Island of Elba.
Then begins the story of Waterloo. Unhappy with his exile, Napoleon planned his triumphant return for a year. He wanted to regain what he had lost, and for that he gathered men, weapons, and strategies.
In 1815, he resumed the French empire and ruled for 100 days. At that time, Napoleon's enemies formed a coalition and decided that they would leave no room for Napoleon.
At that moment the armies of Prussia and England were preparing to invade French territory. Knowing this, Napoleon gathered 72,000 men and set out for the attack. The confrontation happened in the territory that today is Belgium. His enemies had on average 118,000 men and the battle lasted three days, between June 16 and 19, 1815.
The battle was won by the enemies of Napoleon, who was again deposed and exiled on the Island of St. Helena. In its place, the throne was taken over by King Louis XVIII. After that, Napoleon did not return to power, having died of stomach cancer still in exile in 1821.