maybe you can add a little more context to your question (and not post the
same sentence in two places). The most obvious answer is: Caching makes
things faster. But I guess this is not what you want to know. Do you mean
fielddata or filter caches, anything specific you want to know? Any
sourcecode you dug into and have questions about?
Apache, Apache Lucene, Apache Hadoop, Hadoop, HDFS and the yellow elephant
logo are trademarks of the
Apache Software Foundation
in the United States and/or other countries.