What condition is characterized by the inability to move one side of the body?

Hemiplegia specifically refers to the condition where there is a paralysis affecting one side of the body, typically resulting from a neurological event such as a stroke. This condition arises when there is damage to the brain, particularly in areas responsible for motor control. As a result, individuals may experience weakness or the complete inability to move limbs on one side.

While a stroke can lead to hemiplegia, it's important to note that hemiplegia itself is the direct description of the symptomology (loss of movement), rather than the underlying cause. Therefore, within the context of the question, hemiplegia precisely defines the inability to move one side of the body.

Other options, such as a neck injury or infection, may lead to mobility issues but do not specifically indicate the unilateral paralysis characteristic of hemiplegia. A stroke, while it can cause hemiplegia, is not the definition of the condition itself, as it represents the event that may lead to such paralysis rather than describing the characteristic bodily response.