The so-called cycle is a charge-discharge cycle: Apple official website's explanation of "cycle times"
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Cycle Times: This value represents the total number of full and partial discharge cycles in the whole battery life. The battery is discharged to 50% power twice as a discharge cycle, and this discharge cycle is counted as the number of cycles.
1. Before the battery is considered exhausted, its cycle times are limited. The built-in battery of MacBook Pro or MacBook Air can achieve as many as 1000 full charge-discharge cycles before the battery capacity drops to 80% of the initial capacity.
2. About the battery cycle: One-time charging cycle refers to using up all the power of the battery, but it does not necessarily mean charging once. For example, one day you may use your laptop for an hour or more, and then recharge it after using up half of the power. If the next day is still like this, it can be counted as one (not two) charging cycle, so it may take several days to complete a charging cycle.
Every time the battery is used, it will cause loss, which is irreversible in itself, so there is no remedy unless you change the battery.
You have used it for 4-5 years, and it is not normal to cycle it for more than 900 times.