| No | Word | Definition |
| 1 | Quality | Quality is about meeting the needs and expectations of customers. |
| 2 | Software quality | The degree to which a system, component, or process meets customer or user needs or expectations. |
| 3 | Quality factor | represents a behavioral characteristic of a system |
| 4 | Quality criterion | an attribute of a quality factor that is related to software development |
| 5 | Quality control | A set of activities designed to evaluate the quality of a developed or manufactured product. |
| 6 | Quality Assurance | The set of procedures developed and activities done before the product or service is manufactured or delivered to assure of good quality to the customers. |
| 7 | Costs of control | Costs that are spent to prevent and detect software errors in order to reduce them to an accepted level. |
| 8 | Costs of failure of control | Costs of failures that occurred because of failure to prevent and detect software errors. |