Benzene is a widely used industrial chemical. Benzene is found in crude oil and is a major part of gasoline. Its used to make plastics, resins, synthetic fibers, rubber lubricants, dyes, detergents, drugs and pesticides. Benzene is produced naturally by volcanoes and forest fires. In homes, benzene may be found in glues, adhesives, cleaning products, paint strippers, tobacco smoke and gasoline.
A system call is an interface between a user-space application and a service that the kernel provides. Because the service is provided in the kernel, a direct call cannot be performed; instead, you must use a process of crossing the user-space/kernel boundary.
When a process makes requests of the kernel, the request is called a system call. Various kernel designs differ in how they manage system calls and resources. For example, a monolithic kernel executes all the operating system instructions in the same address space in order to improve the performance of the system.he critical code of the kernel is usually loaded into a protected area of memory, which prevents it from being overwritten by other, less frequently used parts of the operating system or by applications.