Param Search on PostsQueryBuilder

[AJProyect]

Hi Thomas! I'm a developer in Spain working for a Tech Education Company. My companions have used your library to consume Wordpress API on C#. Here's my question: For what can I use the param Search on the function PostsQueryBuilder? Is it to get a post wich contains a string on its content?

Further than, my intentions are to get the posts that has modified/created after a specific date. Cheers mate!