Read, View and Limited Access levels in SharePoint appears almost. But there are significant differences.
Read permission level: If a user has Read access to a library, he should be able to browse through the library, open the document to view it either in office client installed in users computer or through office web apps.
View only permission level: If a user has View only permission on a document, user should be able to browse through the library and see the document and can open the document only through office web apps and CANNOT open through client
Limited Access: This access level allows users to access shared resources in the web site. If permissions inheritance is broken and access is provided only for any particular library or list or any item, Limited Access is provided at site level by default to the user. This access means nothing but pass through the site to reach the item where you have access.
Note: A document is only searchable if user has atleast read access on it. If the user has ‘View only’ access, document is not searchable and doesnot show up in search results. With View only access, document can be only accessed through Office web apps.