I'm going to go out on a limb here and guess that your question pertains to a commercial lease and you are asking about CAM instead of CAMS. In many commercial leases tenants pay for the cost of common areas and the maintenance on those areas. The acronym for these costs is CAM for Common Area Maintenance. These costs can be passed through to the tenant. They may be calculated as a fixed amount or an amount based on a percentage of the actual cost.

These costs are not always obvious to those uninitiated to commercial lease negotiations and an unwary tenant can find themselves paying for items in addition to their rent for which they were not prepared. Common CAM costs that a tenant might be responsible for are parking area and sidewalk maintenance, public restrooms, even operational costs such as management fees, insurance, and property taxes.