28. Linux does not differentiate between threads and normal processes.
29. Linux provides an object-oriented device model with device classes,hotpluggable events and user-space device file system(sysfs).
30.
31. The A number denotes the kernel version. It is changed least frequently, and only when major changes in the code and the concept of the kernel occur.
32. The B number denotes the major revision of the kernel. If B is even then kernel is stable else it is unstable.
33. The C number indicates the minor revision of the kernel is only changed when new drivers or features are introduced.
37. API is a function definition that specifies how to obtain a given service(ex.calloc,malloc ,free etc.), while System call is an explicit request to the kernel made via a software interrupt (ex.brk)
45. Thread is simply a new process that happens to share the same address space as its parent
46. Process creation: fork () creates a child process that is a copy of current process. it differs in PID,PPID. exec() loads new executable in to address space. clone() creates a new process(LWP) with its own identity, but that is allowed to share the data structures of its parent.
47. Process Termination: when process calls system call exit(). Process can also terminate involuntarily by signals or exceptions it can not handle or ignore.
48.
49. The kernel implements a O(1) scheduler algorithm that operates in constant time, regardless of the number of threads vying for the CPU. It supports SMP.
82. The sockets layer is the standard API to the networking subsystem and provides a user interface to a variety of networking protocols. From raw frame access to IP protocol data units and up to TCP and the User Datagram Protocol (UDP), the sockets layer provides a standardized way to manage connections and move data between endpoints.