Simmer over low to medium heat, stirring occasionally for about 10 minutes, or until peaches are soft.
Let cool for a few minutes. Reserve liquid from saucepan.
Place peaches in blender and blend until smooth. Add reserved liquid a couple table spoons at a time if needed to reach desired consistency.
Allow to cool completely if serving immediately. If storing, distribute puree into silicone molds or airtight containers. Keep in fridge for up to 4 days or freezer for up to 3 months.
Notes
Of course you can use fresh peaches over frozen, I just prefer frozen because I love that there is no prep work involved. Just peal and slice, and cook time will be a little faster due to not being frozen.