The term for the filtering of blood by kidneys is glomerular filtration. This is a crucial function performed by the nephrons, the functional units of the kidneys. Glomerular filtration allows for the removal of waste products, excess substances, and toxins from the bloodstream, ensuring that only the necessary components, like water and certain solutes, are retained in the body. This process is vital for maintaining fluid and electrolyte balance, regulating blood pressure, and excreting waste through urine.