You can override the behavior of standard buttons—like New, View, or Edit—in Salesforce Classic, Lightning Experience, and mobile independently. You can also override the tab home page that displays when a user clicks a standard, custom, or external object tab.
<apex:page standardController="Account"> <!-- page content here --> </apex:page>
When overriding tabs with a Visualforce page, you can select only Visualforce pages that use the standard list controller for that tab’s associated object, pages with a custom controller, or pages with no controller.
When overriding lists with a Visualforce page, you can select only Visualforce pages that use a standard list controller.
When overriding the New button with a Visualforce page, you can choose to skip the record type selection page. If you do, new records you create aren’t forwarded to the record type selection page. Salesforce assumes that your Visualforce page is already handling record types.
To remove an override: