Perhaps you could ask a more specific question -- this one is very general and will be hard to answer well.
I would say that Hitler came to power because of the unhappiness that was felt in Germany after WWI and the Treaty of Versailles. Because things were so bad in Germany, people were willing to grasp at anything that might help things improve.
Nazism argued that Germans needed to stop trying things like democracy. It argued that they needed to find one man who had a greater "will" than other people. They should follow that person no matter what he said.
This idea seemed attractive because of how bad things were. They were willing to follow Hitler because he seemed to have ideas that might get them out of their problems.
I am not sure any brief summary can be offered on such a topic. There is much to be discussed with it and there are so many divergent vantage points that one can take on it. In my mind, the rise of Hitler can be tied into German disenchantment and despair that followed World War I. As previously stated, the harsh conditions of the Treaty of Versailles made life so difficult for the Germans that there was a level of disengagement with the current political system. The situation was ripe enough for an outsider with a vision to enter and capture the political and moral imagination of the German body politic. Hitler entered this setting with a complete and totalizing view that emphasized a strong German future. He was able to do this because of the employment of the politics of blame. Hitler was able to blame the Western European nations for German problems as evidenced in the Treaty and his perception of a long standing envy of the German nation. Hitler was able to blame the Jewish individuals of the nation for holding jobs and positions that "pure Germans" did not. Hitler was able to blame everyone that was not a part of his party and his belief system and this worked extremely well. Germany, as a whole, was not in the position nor the frame of reference to engage in honest and open self reflection. The politics of blame worked as a better substitute for the German people of the time, which was proven with Hitler's steady and consistent rise to power.
As has been mentioned, the Treaty of Versailles that ended WWI gave rise to conditions in Germany that allowed for the rise of the Nazis. The treaty humiliated the German people. They had to take full responsibility for the war. Their armed forces were severely reduced to almost nothing. And most importantly, the Germans were forced to pay war reparations to the allied forces, huge sums of money that Germany could not afford. In trying to pay these reparations Germany experienced horribly high inflation which pretty much destroyed the German economy. Hitler and the Nazis exploited the humiliation and anger the German people felt by promising to make Germany great again and to restore honor for the German people. Hitler and the Nazis rose to power in several ways. First it must be remembered that Hitler and the Nazis were masters of propaganda and used this tool to maximum effect. Also, some Nazis, known as Brownshirts , used violence to achieve Nazi goals. They would start riots with opposing groups and then blame the chaos on the groups they oppose. Through the use of violence, intimidation, and propaganda, the Nazis rose to power.
Nazism - which was actually an American nickname, short for National Socialism - centered around two key ideas: anti-Jewish beliefs (anti-Semitism) and anti-communist beliefs. Nazism included the idea that the nation was more important than the individual, so there was no need for individual rights, and all power was given to the state. As part of this new government, a "master race" would be created of Aryan whites, to lead the new German Empire.
Germans liked the idea (some of them) and gave rise to Hitler as thir leader because he restored order in the country, improved the economy, gave people jobs and confidence, and restored their pride in their nation.