Non-performing assets (NPAs) are loans that are in default or close to being in default. The document discusses NPAs in Indian banks, including what qualifies a loan as an NPA, how NPAs are classified and provisioned for, and reasons why loan accounts may become NPAs, including internal factors within banks and borrowers as well as external economic factors. Key points are that an asset is considered non-performing if interest or principal has been due for over 90 days, NPAs are classified as substandard, doubtful or loss, and banks must make provisions against NPAs which reduces their profits.