Glucose tests

Amanda 🐼 • With my husband for 25 years, married 15 💍 Postpartum/Newborn RN 💉 Addison Sarah born 1/1/16 🎀 Skylar Melina born 12/2/23 🩷
What is the difference between the glucose tolerance and glucose challenge tests? And when do you generally get these done? 😁