Complex sentence: Curds are a dairy product obtained by "curdling" (coagulating) milk with rennet or any edible acidic substance such as lemon juice or vinegar, and then allowing it to set.
Split into simpler sentences: Curds are a dairy product obtained by "curdling" (coagulating) milk. The coagulation can be caused by adding rennet or any edible acidic substance such as lemon juice or vinegar, and then allowing it to set.