i would like to know if anybody has already change the mode of grid.
By defaut, in list of orders, we have this mode :
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you cannot change this "on the fly".
What you have there are 2 types of grids with 2 different implementations.
The second on is the "new trend" grid that you can find in the products list, customers, cms pages and blocks and a few other entities and are implemented via ui-components.
You can see how it is defined in here
The second one is the "old version" that still exists for a few modules but you should not use that one.
You can see an example in the backup module.
This one does not use ui-components. It's just a simple layout file with block definitions inside it.