The ‘Build Object Search Index’ feature in the BC14 Development Environment makes objects searchable in the webclient according to the Microsoft documentation: https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/upgrade/upgrade-pages-report-for-search
However in another Microsoft article:
Running C/SIDE and AL Side-by-Side https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/devenv-running-cside-and-al-side-by-side
you should run a command in order to generate symbols. But actually the Build Object Search Index performs the same action. In my opinion it’s just easier sometimes to generate symbols by using the ‘Build Object Search Index’ instead of opening a Console and running the command as mentioned AND with the disadvantage of no progress in the Console which you do have in the Development Environment: