How to provide external access to a site? Know this about SharePoint.

External access in SharePoint allows users to securely share content with people outside their organization, such as partners, vendors, or clients. Here are some key points:

• Sharing options: You can share files, folders, or even entire sites with external users. Depending on the recipient, they may need to verify their identity using a one-time passcode or sign in with a Microsoft account.

• Guest accounts: When using Microsoft Entra B2B integration, guest accounts are created for external users, and collaboration settings apply.

• Permissions management: Permissions can be tailored for team sites, communication sites, and hub sites. Microsoft 365 groups simplify permission management by associating services like SharePoint, Planner, and shared calendars.

• Security features: You can restrict editing permissions, block downloads, and stop sharing at any time to maintain control over shared content.

Actually, this article is focused on entire sites, you can follow these steps:

1. You need to enable the external sharing. Please refer below
   Turn external sharing On or OFF.
   
2. Then you need assign visitor permission on the site by following below steps
1. Go to SharePoint site > Gear icon from top right corner > Site permission > Site settings.
2. Advance permission for sharing > Site Visitors> New > Enter the email address of the people with who you want to share the SharePoint site.
3. Click in OK or SAVE CHANGES.

And with that the entire site has a permission for the user that you allow.

You can check the Microsoft Documentation for the External Sharing options for more information in the link below:

https://docs.microsoft.com/en-us/sharepoint/turn-external-sharing-on-or-off