The FamilySearch.org Worldwide Indexing Event starts tomorrow, October 20, 2017, and continues for three days over the weekend.
You may take indexed records for granted. Whenever you search on FamilySearch.org or any other genealogy website, you are taking advantage of indexing done by someone else. Without that effort, you would be reduced to searching records in the "old way" page by page and line by line. By providing an index, you are helping yourself and others find valuable records about your own and their own ancestors.