kinldy explain what is difference between functional and non functional requirements with examples

kinldy explain what is difference between functional and non functional requirements with examples

Software requirement is description of what is required from software to do. Requirements at different level of detail also mean to serve different purposes. These include business requirements, user requirements, functional requirements and non functional requirements.

Functional requirements are required functions which must build into the product (software) to enable users to accomplish their tasks. Functional requirements define operations (behavior) of software. Non functional requirements are quality requirements or non behavioral requirements. These are constraints on operation of software. These are used to describe external system interfaces, design and implementation constraints, quality and performance attributes. These also include regulations, standards, and contracts to which the product must conform.

For example, we want to develop spelling checker. Then functional requirements would be: find and highlight spelling mistakes, suggest replacements, provide selection option to user etc. Non functional requirement can be “it should be able to work on all existing platforms (windows, Vista, Linux etc).