Although they sound pretty similar, plates and sheets are two different types of metal bodies. There is a minute yet significant difference between the two. Sheets are used when there is a requirement for light-weighted material that does not offer long time durability. Whereas metal plates are highly durable and last for longer periods

Sheets:

Sheets are made out of steel which happens to be an alloy with enhanced physical and chemical properties. It is a very thin and fine sheet of metal that has been rolled and hammered to be as flat as possible. It can be manufactured using numerous types of metals. Commonly used metal is steel, copper, and aluminum. It is a thin piece of metal but is thicker than foil. Foil is made purely out of gold, aluminum, and silver and is exceptionally thin. On the other hand, metal sheets are used in applications that do not require durability like building structures. 

Plates:

The major difference and probably the most important one between plates and sheets is their thickness. Stainless Steel 316 Plates have a thickness of 6mm and above. It is used in applications and industries that demand durability. Plates are widely used in the automobile industry where durability is quintessential to pass several tests like the crash test. Plates can be produced from any type of metal like aluminum, copper, etc. 

Besides the thickness, sheets and plates vary from grade to grade. The differences are specific to the type of material used. Plates are way more durable than sheets, and sheets provide the advantage of light weightiness. For a more definitive difference between the two i.e., sheets and plates, it is pivotal to refer to particular grades and standard specifications.

Conclusion 

the most essential property that differs between a metal plate and sheet is the thickness or gauge of the metal used. Both sheets and plates have distinct applications varying based on specifications of the project and durability requirements.