If a molecule is moved against the concentration gradient, it means the molecule is being transported from an area of lower concentration to an area of higher concentration. This process is called active transport and requires the input of cellular energy, often in the form of ATP, because molecules naturally tend to move from high to low concentration (down the gradient) without energy input. Transporting molecules against the gradient allows cells to accumulate essential substances like ions, nutrients, or glucose even when they are in lower concentrations outside the cell. Proteins in the cell membrane facilitate active transport by specifically binding and moving these molecules across the membrane against the gradient. This mechanism is crucial for maintaining cellular functions, nutrient uptake, and ion balance.