  Coronal loops are fundamental building blocks of the solar active regions and
the corona. Therefore, a clear understanding of the physics of coronal loops
will help us understand the physics of active region heating in particular and
coronal heating in general. This requires a precise measurement of physical
quantities such as electron densities and filling factors, temperatures, and
flows in coronal loops. In this paper we have carried out an investigation of a
spatially well resolved coronal loop using the EIS onboard Hinode to measure
the above mentioned physical quantities. Based on this study we find that a
nano-flare model could explain most of the observed characteristics of this
loop.
