Ramadan Kareem is the name of the glorious month of Ramadan. People sometimes say "Ramadan Kareem" or "Ramadan Mubarak" as a greeting to other muslims during this period.
Ramadan is the ninth month of the Islamic calendar and is the time when Muslims observe a fast from sunrise to sunset. While fasting is usually defined as refraining from food and water, many Muslims also refrain from smoking and sexual relations and try not to swear or lose their temper while fasting.
Muslims who are exempt from fasting include elderly or sick women, women who are pregnant or have just given birth and women who are menstruating. Instead of fasting, these women can provide food to a homeless person or donate enough money to cover the cost of feeding a person for the month of Ramadan.