The phrase "to increase" means to make something bigger, greater or more than it currently is. It can refer to an action taken to raise the amount, level, number, value or size of something. For example, if a company wants to boost its sales, they may implement strategies to increase their customer base and sales volume. Similarly, when someone works hard to improve their fitness levels, they are increasing their physical strength through exercise. In summary, "to increase" means to make something more than it currently is or was before.