The grid will be placed in 2 behaviour which you can choose, arithmatic order or geometric order. As the name implies, arithmetic will give you fixed gap between grids, meanwhile geometric will give you fixed percentage gap between grids. For example 100-200, arithmetic will put order on 100,120,140,…200. Meanwhile geometric will put 100,120,144,…. (every 20% gap)
Both of them is valid into the market, just make sure to choose which one suits your trading style and trading plan better.