This blog cover the difference between UI components grid and layout grid in Magento. Magento introduces a new way to create a grid in the admin area called UI grid. It is flexible and easy to extend.
There are key differences listed below-
UI Components Grid
Advantages-
1. It is mostly configuration. So you write less code.
2. You get a cool grid with show/hide columns, drag/drop columns, full-text search, inline edit, export built-in, and maybe others.
3. It can easily be extended with just another XML file in a different module.
4. Any new feature Magento rolls out for the grids you will get it automatically in your grid.
Disadvantages-
1. Difficult to debug.
2. Difficult to build nonstandard grids.
3. Not very much control over what happens.
Layout Grid
Advantages-
1. You got full control of what happens.
2. Relatively easy to build non-standard grids.
3. Easy to debug.
4. You can use your knowledge from Magento1 to do it.
Disadvantages-
1. Grid is not that flexible or extensible.
2. You need to write the same code over and over again.
3. More code to test or that can break.
Source
Related blog – Magento Product Type
