On page search module provide functionality to search on single page. It is replacement of CTRL+F of browser.
If you are using infinity views load more , then it may possible that user may have very large page. Then if user want to search on this long page , then you may required this module.
You can highlight the certain keyword that you are interested in for easy spot.
You just have to type the search phrase in textbox.
Drupal module link : OPS
This module give you a search box in block ,Assign this block in your desired location to you search functionality on this current page.
As you will type this search phrase will got highlight. There is configuration to change the background color of the search phrase.
In case of very long hight page , sometimes user require to highlight the phase then on page search ops module is very usefull