When records are created in Salesforce, How it is queued for Indexing?

For data to be searched, it must first be indexed. The indexes are created using the search indexing servers, which also generate and asynchronously process queue entries of newly created or modified data. After a searchable object’s record is created or updated, it could take about 15 minutes or more for the updated text to become searchable.

Salesforce performs indexed searches by first searching the indexes for appropriate records, then narrowing down the results based on access permissions, search limits, and other filters. This process creates a result set, which typically contains the most relevant results. After the result set reaches a predetermined size, the remaining records are discarded. The result set is then used to query the records from the database to retrieve the fields that a user sees.