Difference between peritoneal dialysis and hemodialysis?

In medicine, hemodialysis (also haemodialysis) is a method for removing waste products such as potassium and urea, as well as free water from the blood when the kidneys are incapable of this (i.e. in renal failure). It is a form of renal dialysis and is therefore a renal replacement therapy.

In medicine, peritoneal dialysis is a method for removing waste such as urea and potassium from the blood, as well as excess fluid, when the kidneys are incapable of this (i.e. in renal failure). It is a form of renal dialysis, and is thus a renal replacement therapy.

hemodialysis when the kidneys are incapable of waste products such as potassium and urea, as well as free water from the blood It is a form of renal dialysis and is therefore a renal replacement therapy.
and peritoneal dialysis It is a form of renal dialysis, and is thus a renal therapy

one is thru renal the other is a replacement

Peritoneal dialysis:
Technique that uses the patient's own body tissues inside of the belly (abdominal cavity) to act as a filter. The intestines lie in the abdominal cavity, the space between the abdominal wall and the spine. A plastic tube called a "dialysis catheter" is placed through the abdominal wall into the abdominal cavity. A special fluid is then flushed into the abdominal cavity and washes around the intestines. The intestinal walls act as a filter between this fluid and the blood stream. By using different types of solutions, waste products and excess water can be removed from the body through this process.

Hemodialysis:
A medical procedure that uses a special machine (a dialysis machine) to filter waste products from the blood and to restore normal constituents to it. This shuffling of multiple substances is accomplished by virtue of the differences in the rates of their diffusion through a semipermeable membrane (a dialysis membrane).

Although hemodialysis may be done for acute kidney failure, it is more often employed for chronic renal disease. Hemodialysis is frequently done to treat end-stage kidney disease. Under such circumstances, kidney dialysis is typically administered using a fixed schedule of three times per week.

Hope this helps