The definition of symbiosis has varied among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any type of persistent biological interaction (i.e. mutualistic, commensalistic, or parasitic).
The Golden Pledge, which is a System Plus Warranty with a 20 year leak guarantee, can pay for itself within the first ten years, sometimes many times over. The System Plus transforms the normal warranty by removing the small print.
A warranty is usually a written, contractual promise that attests to the quality of a specific, purchased product for a certain amount of time. Should the product become defective while it is still under warranty â say, within one year of its purchase â the company is bound by the warranty to repair or replace the item. A guarantee is also a promise regarding product quality, and it may even be written into a warranty contract. However, guarantees are generally less likely to be written, and are often not as clearly defined as warranties.