Business Connectivity enables me to connect to an external data source. Allowing the SharePoint user to update\ delete\ insert rows to a table through the SharePoint UI.
Works well with one table, not with a few tables.
SharePoint Designer enables us to edit page properties, CSS files etc. If we’re writing code, we may prefer to write it in Visual Studio and then paste it into the designer.
We can use it for manual versioning when we copy files from our test area to our production area.
You should avoid editing dashboard pages in the SharePoint Designer as it can lead to breaking connections between web parts and pages.
We need to use F5 key and at times closing a page and re-opening it to see the changes we defined take effect.
We should also take notice to the tabs that are open in the Designer as the Designer enables us to open parts more than once. That could lead to us having a change we haven’t saved for a page in one tab, and then another tab where we’re editing an old version of the same page. This could lead to one of the tabs not taking effect.
Most of the things that we can edit through SharePoint Designer we can also edit through the web UI. Defining a connection in the BCS can be done only through the SharePoint Designer.
A site of itself to manage the entire front – end sites the users see. Manages sites, pages and services on those sites.