What changes occurred due to Normans taking over France?

In the year 911, the Viking chief Rollo established the first permanent Norman settlement in what is now France with the treaty of Saint-Clair-Sur-Epte. This marks a period which would profoundly change the nature of the Normans (signifying the Vikings in France) and the Normandy region of France itself.
With this treaty, Rollo and his fellow Normans promised not to invade or pillage other parts of France, effectively ending a period of violent raids that had reached as far as Paris itself. Furthermore, the Normans officially adopted Christianity and abandoned their older pagan gods. The Normans also adopted the French form of feudal government and politics as well as language and social customs.
The region itself and its inhabitants were also greatly changed as they came under the control of the Normans. Norman warriors usually married local Frankish women, thus greatly impacting the makeup of the population. They established many schools, churches, and monasteries. They eagerly defended the kingdom from invaders and aided in the conquest of Brittany, thus expanding the nation's borders. The Normans also established many new trade routes around Europe and brought more exotic goods into France, establishing contacts with other nations, particularly Byzantium.
The impact of the Normans in France can still be seen today in the borders of the region of Normandy and certain words in the French language.
https://www.durhamworldheritagesite.com/history/normans