When the Normans settled in Ireland they introduced their way of life: The feudal system.

The King was the owner of all Norman lands in Ireland. He gave this land to his loyal lords, and they could keep it as long as they remained loyal. In Ireland these Norman lords were really independent rulers.
When a Norman lord dies his eldest son inherited his title and lands. This system of inheritance was called.........

Norman lords lived in castles. At first these were motte-and-bailey casles, such as Granard, Co. Longford, Callan, Co. Kilkenny, or Ardscull, Co. Kildare. But these castles were not strong enough to stop Irish attacks, so stone castles were built. Examples are Trim, Co. Meath; Adare, Co. Limerick; Maynooth, Co. Kildare; and Athenry, Co. Galway.

Trim Castle, Co. Meath was built by the De Lacys. It looked like this in 1250.
Although life in the castle was not very comfortable, the lord and his family were much better off than everybody else. Their clothes were made from linen, silk, or velvet. They did not eat many vegetables or sweet things. Instead they ate lots of meat: beef, lamb, pork, venison and chicken.
Agriculture
The Normans now owned the best land in Ireland and farmed it on the open-field system.
Towns
May new towns were built during Medieval times in Europe.
Local lords and even Kings encouraged people to build towns. In Ireland the Normans built many nw towns for this very reason. Many of these towns were given charters. This allowed them to trade freely with other towns, set up by guilds, collect taxes, and sometimes to elect their own mayor.
Some of these towns built walls to keep unwanted people out. But they were mainly built for protection. The people of New Ross, Co. Wexford built walls because they were afraid of being caught in the middle of the war between two lords, Maurice FitzMaurice and Walter de Burgh. The citizens of the town had to pay a tax each year to repair the walls.