In a Linked CSE the specification of the search engine is hosted on your website. In a Google Stored CSE the specification is stored at Google.
# Advantages of Linked CSE's
Linked CSEs overcome these limitations of Google Stored CSEs.
With Linked CSEs, you host the CSE specification on your web site and include the url for this specification in your CSE search request. Google retrieves the CSE specification from your website when your user searches in the CSE.
This has several very important benefits: * You can easily convert your data source to a Custom Search Engine. * You can automatically generate any number of CSEs, each possibly tuned to a particular user, the particular page, time of day, etc. In fact, you can generate CSEs on demand, in response to a users query or a page on your site that your user is searching from. We provide several interesting tools, such as creating a Linked CSE out of the links on a page, that you can use. * You can easily update your Linked CSE definitions without pushing data to Google. * There are no global, per user annotation limits.
You can now exploit the full power of your ideas to dynamically generate CSEs. Some interesting sources of data you could use to create CSEs are iCal feeds, your referrer logs and your users' bookmarks or browsing history. You could even change the look and feel of your CSE in response to the health or traffic of your website. Linked CSEs are always free, ad-supported CSEs; the Linked CSE mechanism cannot be used to host CSE specifications for Google Site Search.
# Disadvantages of traditional CSE's
With a traditional Google Stored CSE, you create the CSE either by logging in and using the wizard or writing an XML file and uploading to Google (via the Advanced tab). The search box code that you use refers to this specification stored at Google using the "cx" parameter. To change any aspect of the CSE, you have to either use the Control panel or upload the new XML specification.
This imposes several limitations: * Creating and maintaining a CSE is a manual process. * It is difficult to create a very large number of CSEs, say one for each of your users or a slightly different one for each of your pages. * It is difficult to use other data sources such as iCal, RSS, Google Base, etc. to programmatically create CSEs.