1. Meaning:
"gallop on horseback" refers to driving a fast horse with a whip in hand, which is a metaphor for accelerating progress and contributing to great things. This idiom emphasizes a state of initiative and quick action.
"gallop" is to drive a fast horse with a whip in your hand and make it run fast. It describes fast marching. This idiom emphasizes a fast-moving and unrestricted state.
2. Usage:
"Riding on horseback" is often used to describe the rapid development of things, undertakings and progress. For example, "in this Internet age, the spread of information is as fast as riding a horse."
"Riding on horseback" is more used to describe the performance of a person or a team in a certain task or competition, emphasizing quick action and outstanding ability. For example, "in this competition, their team rode horses, passed all the way, and finally won."
Generally speaking, "galloping on horseback" and "galloping on horseback" both describe galloping of horses, but their meanings and usages are different and need to be chosen according to specific contexts.