What is the difference between Direct and Indirect Realism?

Direct realism is the common sense view within the philosophy of mind which states that objects are as they appear to be, all objects are made of matter and that our perceptions are entirely correct. Indirect realism was developed by John Locke and makes the more nuanced claim that we interact with all object through a 'veil of perception' and so our perceptions are mitigated from the actual characterisitics of the object. Indirect realism argues that there are primary and secondary qulaiites of objects - primary qualities such as length are objective and are within the object, unaffected by the veil of perception whereas secondary qulaities, such as colour, are subjective and are affected by the veil. 

Indirect realism aims to account for how we, as humans, have differing perceptions of the world - such as two people discerning the colour or temperature of an object differently - whilst still maintaining that matter exists separate from and independent of ourselves.