1. A mobile terminal comprising: a memory storing at least one task group including two or more tasks; a controller performing a task group operation such that at least two of the two or more tasks belonging to the at least one task group are executed simultaneously in response to a single input without requiring separate inputs for executing each of the two or more tasks; and a touchscreen display displaying the at least one task group, an execution screen associated with at least one of the executed two or more tasks, and a plurality of task identifiers, each of the plurality of task identifiers representing a corresponding one of the two or more tasks, wherein the two or more tasks belonging to the at least one task group are correlated such that a single control operation is simultaneously applied to each of the two or more tasks in response to the single input to execute the two or more tasks simultaneously, wherein the task group operation comprises a simultaneous background operation, a simultaneous foreground operation, and a combination of a foreground operation and a background operation, each operation executed independently, wherein the simultaneous background operation comprises simultaneous background execution of all tasks in a same task group in response to the single input such that no execution screen associated with the execution of the all tasks is displayed on the touchscreen display, wherein the simultaneous foreground operation comprises simultaneous foreground execution of the all tasks in the same task group in response to the single input such that execution screens associated with the execution of the all tasks are displayed together on the touchscreen display, and wherein the combination of the background operation and the foreground operation comprises foreground execution of a first task in the same task group and background execution of a second task in the same task group that are performed selectively and simultaneously in response to the single input such that a first execution screen associated with the execution of the first task is displayed on the touchscreen display while no execution screen associated with the execution of the second task is displayed.