Central venous catheterization is a medical procedure used to place a thin, flexible tube, called a catheter, into a large vein, usually in the neck, chest, or groin. This allows healthcare providers to administer medications, fluids, or nutrients directly into the bloodstream, monitor central venous pressure, and draw blood samples. The procedure is typically performed under sterile conditions and may involve the use of ultrasound to guide the catheter's placement. Central venous catheters are commonly used in patients who require long-term intravenous therapy, such as those undergoing chemotherapy or those with severe illnesses.