Final answer:
The balance of the accumulated depreciation account reflects the total depreciation recorded for plant assets over time, reducing their book value and indicating the allocation of their cost over the assets' useful lives.
Step-by-step explanation:
The balance of the accumulated depreciation account represents the total amount of depreciation expense that has been recorded over time for plant assets. This balance is a contra asset account that reduces the book value of the plant assets to reflect their usage and age. Accumulated depreciation accumulates as the plant assets are used and represents the allocation of the cost of the assets over their useful lives.
For example, if a company purchases machinery for $100,000 with an expected useful life of 10 years, it might depreciate the machinery at a fixed rate of $10,000 per year. After 5 years, the accumulated depreciation for the machinery would be $50,000. This means that the machinery's book value (cost minus accumulated depreciation) would be $50,000, indicating a decline in value due to wear and tear, usage, or obsolescence over time.