A home inspection covers most aspects of the building. See home inspection. There are limitations to what a typical home inspection covers. Some of the things that are beyond the scope of the home inspection, which you might want to consider having a qualified person inspect are:
Septic Systems - The home inspector will test for 'functional drainage' during normal use of fixtures. The drainage plumbing will be inspected. If the house has a septic system it is generally a good idea to have a specialist evaluate the system.
Water Supply Systems - The home inspector will test only for 'functional flow' during normal use of plumbing fixtures. The distribution plumbing will be inspected. If the house does not have public or community water it is generally a good idea to have the supply system (well, spring, etc) tested for water quality and quantity.
Electrical Generation Systems - The home inspector will test for presence of power, will test electrical fixtures, appliances and receptacles and will identify and inspect the electrical panel and distribution wiring. Power generation/control systems should be evaluated by a specialist.
Wood Destroying Organism Identification - The home inspector will inspect for visible evidence of wood destroying organisms (e.g. fungus, termites) but only a state licenced WDO (pest) inspector can legally identify these. A state licenced pest inspector may also give a price quote to repair/remediate pest related damage and/or treatment.
Geological Items - The home inspector will look for visual evidence of geological type issues (e.g. under-mining of the foundation, foundation cracks, erosion) and recommend further evaluation as required, but it is beyond the scope of the inspection to determine the stability of slopes. If the house is on or near a steep slope/hill it is generally a good idea to have a geo-technical engineer evaluate the property.