Measurement is defined as the ability to precisely quantify the physical, dimensional, or electrical properties of materials. There are numerous measurement tools used in the Fab to monitor the quality of the process relative to its designed specifications. Generally, if all materials and processes are within specification, the the chip will operate as designed.
Inspection is defined as the ability to observe and quantify defects.
As fine geometries get down to below 0.2 micron, the ability to observe these defects becomes more challenging and expensive. As chip densities increase, the volume of inspection and measurement data also increases - hence the need for sophisticated software tools for yield data management and analysis.