Title: Task (computing)
Content:   In computing, a task is a unit of execution or a unit of work. The term is ambiguous; precise alternative terms include process, light-weight process, thread (for execution), step, request, or query (for work). In the adjacent diagram, there are queues of incoming work to do and outgoing completed work, and a thread pool of threads to perform this work. Either the work units themselves or the threads that perform the work can be referred to as "tasks", and these can be referred to respectively as requests/responses/threads, incoming tasks/completed tasks/threads (as illustrated), or requests/responses/tasks.
Title: Input (computer science)
Content: Mouse ; Keyboard ; Touchscreen ; Microphone ; Webcam ; Softcam ; Touchpad ; Trackpad ; Image scanner ; Trackball In computer science, the general meaning of input is to provide or give something to the computer, in other words, when a computer or device is receiving a command or signal from outer sources, the event is referred to as input to the device. Some computer devices can also be categorized as input devices because we use these devices to send instructions to the computer, some common examples of computer input devices are:  Also some internal components of computer are input components to other components, like the power-on button of a computer is input component for the processor or the power supply, because it takes user input and sends it to other components for further processing. In many computer languages the keyword "input" is used as a special keyword or function, such as in Visual Basic or Python. The command "input" is used to give the machine the data it has to process.
Title: Input queue
Content:  In operating systems, processes are loaded into memory, and wait for their turn to be executed by the central processing unit (CPU). CPU scheduling manages process states and decides when a process will be executed next by using the input queue.
Title: Job (computing)
Content:  In computing, a job is a unit of work or unit of execution (that performs said work). A component of a job (as a unit of work) is called a task or a step (if sequential, as in a job stream). As a unit of execution, a job may be concretely identified with a single process, which may in turn have subprocesses (child processes; the process corresponding to the job being the parent process) which perform the tasks or steps that comprise the work of the job; or with a process group; or with an abstract reference to a process or process group, as in Unix job control. Jobs can be started interactively, such as from a command line, or scheduled for non-interactive execution by a job scheduler, and then controlled via automatic or manual job control. Jobs that have finite input can complete, successfully or unsuccessfully, or fail to complete and eventually be terminated. By contrast, online processing such as by servers has open-ended input (they service requests as long as they run), and thus never complete, only stopping when terminated (sometimes called "canceled"): a server's job is never done.
Title: Input/output
Content:  In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals or data received by the system and outputs are the signals or data sent from it. The term can also be used as part of an action; to "perform I/O" is to perform an input or output operation. I/O devices are the pieces of hardware used by a human (or other system) to communicate with a computer. For instance, a keyboard or computer mouse is an input device for a computer, while monitors and printers are output devices. Devices for communication between computers, such as modems and network cards, typically perform both input 
Title: Execution (computing)
Content:  Execution in computer and software engineering is the process by which a computer or virtual machine reads and acts on the instructions of a computer program. Each instruction of a program is a description of a particular action which must be carried out, in order for a specific problem to be solved. Execution involves repeatedly following a 'fetch–decode–execute' cycle for each instruction. As the executing machine follows the instructions, specific effects are produced in accordance with the semantics of those instructions. Programs for a computer may be executed in a batch process without human interaction or a user may type commands in an interactive session of an interpreter. In this case, the "commands" are simply program instructions, whose execution is chained together. The term run is used almost synonymously. A related meaning of both "to run" and "to execute" refers to the specific action of a user starting (or launching or invoking) a program, as in "Please run the application."
Title: Task (computing)
Content:  In the sense of "unit of execution", in some operating systems, a task is synonymous with a process, and in others with a thread. In non-interactive execution (batch processing), a task is a unit of execution within a job, with the task itself typically a process. The term "multitasking" primarily refers to the processing sense – multiple tasks executing at the same time – but has nuances of the work sense of multiple tasks being performed at the same time. In the sense of "unit of work", in a job (meaning "one-off piece of work") a task can correspond to a single step (the step itself, not the execution thereof), while in batch processing individual tasks can correspond to a single step of processing a single item in a batch, or to a single step of processing all items in the batch. In online systems, tasks most commonly correspond to a single request (in request–response architectures) or a query (in information retrieval), either a single stage of handling, or the whole system-wide handling.
Title: Input queue
Content:  In computer science, an input queue is a collection of processes in storage that are waiting to be brought into memory to run a program. Input queues are mainly used in Operating System Scheduling which is a technique for distributing resources among processes. Input queues, not only apply to operating systems (OS), but may also be applied to scheduling inside networking devices. The purpose of scheduling is to ensure resources are being distributed fairly and effectively; therefore, it improves the performance of the system. Essentially, a queue is a collection which has data added in the rear position and removed from the front position. There are many different types of queues, and the ways they operate may be totally different. Operating systems use First-Come, First-Served queues, Shortest remaining time, Fixed priority pre-emptive scheduling, round-robin scheduling and multilevel queue scheduling. Network devices use First-In-First-Out queue, Weighted fair queue, Priority queue and Custom queue.
Title: Command (computing)
Content:  In computing, a command is a directive to a computer program to perform a specific task. It may be issued via a command-line interface, such as a shell, or as input to a network service as part of a network protocol, or as an event in a graphical user interface triggered by the user selecting an option in a menu. Specifically, the term command is used in imperative computer languages. The name arises because statements in these languages are usually written in a manner similar to the imperative mood used in many natural languages. If one views a statement in an imperative language as being like a sentence in a natural language, then a command is generally like a verb in such a language. Many programs allow specially formatted arguments, known as flags or options, which modify the default behaviour of the program, while further arguments may provide objects, such as files, to act on. As an analogy to a natural language, the flags are adverbs, while the other arguments are objects.
Title: Burroughs MCP
Content:  from user input, which would be input from a network device with a GUI interface). Tasks waiting on user input or file reads would not normally be listed as waiting entries for operator attention. Another reason for a task to be waiting is waiting on a file. When a process opens a file, and the file is not present, the task is placed in the waiting entries, noting that it is waiting on a certain file. An operator (or the user that owns the process) has the opportunity either to copy the file to the expected place, or to redirect the 

Question: input that tells the computer which task to execute is?
Answer: source code.
A computer program.