What is the difference between a schema and a heuristic? I am trying to understand the basic differences, in layman's terms, between a schema and a heuristic
A heuristic consists of preferences that help you decide in a situation where you do not have enough information or do not care enough to make an informed decision. For example, when you want to buy yoghurt, but are no nutritionist, you might decide on which yoghurt you buy by the familiarity of the brand name (you prefer the familiar, this is called the familiarity heuristic) and other aspects that have nothing to do with the yoghurt itself.

A schema is a workflow or storyboard that tells you what to do in a recurring situation. For example, when you go shopping you might follow an internal script to make shopping more efficient: you pick the same products in the same sequence every time. You know in advance what you will buy, there are no decisions involved, in fact you ignore all alternative products. A schema allows you to navigate familiar, recurrent and similar situations by following the same sequence of actions.