Can somebody please explain these statements in a summary, just short and precise.

1. Depreciation is accounted to record the wear and tear of the building due to use.
2. Depreciation is a way of accumulating cash for future use i.e. either for repairs, renewal or replacement of the asset.
3. Also, the realty prices do not stay the same always, they may increase or decrease depending on the market conditions and year's increase is not indicative of the future.
4. As per historical concept in accounting, all assets are recorded at their historical cost i.e. the acquisition cost and any subsequent increase or decrease of the asset is ignored and only depreciation is charged.
5. Taking in to consideration the prudence concept, any gains which have not materialized must not be recorded and only anticipated losses must be accounted for.
6. A revaluation of the asset can be done if the business feels necessary to reflect the true value of the asset and increase the value accordingly.

Thanks in Advance.