Yes, Sumeria and Sumer refer to the same ancient civilization. The terms are often used interchangeably to describe one of the earliest known civilizations in the world, located in the southern part of Mesopotamia, which is modern-day Iraq.
Sumer is the name commonly used by historians and archaeologists to refer to this civilization. The term Sumeria is a less common variant but essentially means the same thing. Both terms denote the same region and culture that flourished around 4500 BCE to 1900 BCE.
The Sumerians are credited with many significant achievements, including the development of cuneiform script, one of the earliest forms of writing, and the establishment of city-states such as Uruk, Ur, and Eridu. Their contributions to mathematics, astronomy, and law have had a lasting impact on subsequent civilizations.