Matrix Changes in Craft 5

In ver­sions pri­or to Craft 5, Matrix was its own sep­a­rate ele­ment type. With the move of Matrix Blocks to entries, here’s how it’ll unfold:

1. Matrix Blocks become Entries — each block you save, e.g. a CTA field with a URL field, and a text link field, will be saved as entries in the Craft data­base. These will have some sim­i­lar prop­er­ties to the Entries you’re used to.
2. Matrix Block Types become Entry Types — you will cre­ate or choose an Entry Type for each block type you want in your Matrix field. Entry Types are a stand­alone thing now, so you can use any entry type in your Matrix block. 
3. Matrix Fields become Glob­al Fields — pri­or to Craft 5, you cre­ate fields in a Matrix Field block as one-off, non-reusable, non-glob­al fields. Now all Matrix Fields are cho­sen from stan­dard fields (via the Entry Type). So, this means you can cre­ate one, say, Rich Text Field, and reuse that fields across Entry Types and field lay­outs for all sec­tions and Matrix block types.

As part of the migra­tion to Craft 5, Craft will move your exist­ing Matrix fields (all Matrix blocks, block types, and fields) to their new loca­tion. Entries will be cre­at­ed for each Matrix Block, new Entry Types for each Block Type, and glob­al fields for each field in a Matrix block type.

The result may be that you have a lot of fields to sort through, con­sol­i­date, and clean up. If you have a very com­plex Matrix set­up, let’s say with a page builder style Matrix field, then you may need to do some work post-upgrade.