Salesforce Dynamic Forms

This helps to migrate the fields and sections from your page layout as individual components into the Lightning App Builder.

You can configure them just like the rest of the components on the page, and give the users of that page visibility to only the fields and sections that they need by using filter option provided.

Advantages:

• You can place fields and sections like in page layouts but its more flexible here.
• Use visibility rules to show and hide fields and sections like using filter.
• Manage the fields and sections on your pages in the Lightning App Builder without going to the page layout editor.
• Reduce the number of page layouts you need with component visibility rules.
• Single assignment model for the Lightning page instead of the dual model of assigning a Lightning page and a page layout. 

Set up Salesforce Dynamic Forms:

You can create Lightning Page or Migrate Lightning Page. Go to the Lightning page of any custom object that you want to upgrade then select the 'Record Detail' or 'Highlights Panel' component, and choose 'Upgrade Now'.

You can also create a brand new page by going to your custom object, selecting 'Lightning Record Pages', then choosing 'New'.

Steps: object manager | the object | go to lightning page of the object | click New

Post migration or post creation of the new Lightning record page, you will see the option to add a 'Field Section' component which will then enable you to add fields directly to the Lightning record page like you can remove some tabs like Details tab or create a custom tab called 'Information'. Drag drop the 'Field Section' component.

Add fields to a component like add Field Section component from left and drop as per need. You can also name the field section like in page layout.

For Example: First drag drop fields you want to make visible to everyone. You can also change the access to fields like Read Only or Required

You can even make the fields, specific component or entire component etc. visible based on specific condition adding filter criteria to it that is, the fields or component can be made appear or disappear as on the user edits and save of the records. For improved load and performance, you may use tabs or accordion as well.

Note:

• Dynamic Forms is currently only available for custom objects not standard objects
• Dynamic Forms are not supported on record pages that use pinned-region or custom page templates.
• As of now, the new Field Section component and the Field components are not supported on mobile. Any migrated pages will automatically have a new 'Record Detail – Mobile' component added but you need to remember to add this if you’re building a page from scratch.

Reference:

https://help.salesforce.com/s/articleView?id=sf.dynamic_forms_overview.htm&type=5