Casing, often referred to as a cover, is a protective layer that encases an object or device. It serves to shield the contents from environmental factors such as dust, moisture, and physical damage. Common examples include the outer shell of electronic devices like smartphones and laptops, which help maintain their functionality and appearance. In various industries, casing is crucial for safety and durability. For instance, in the oil and gas sector, casing is used in drilling to stabilize the wellbore and prevent contamination. Similarly, in packaging, casing protects products during transportation and storage, ensuring they reach consumers in good condition.