Clicking on the Indices tab displays the summary details of each index present in the cluster, as shown in the following screenshot:
For each index, it provides information, such as the name of the index, status of the index, total count of documents present, disk space used, index rate per second, search rate per second, and number of unassigned shards.
Clicking on an Index name provides detailed information about that index. The detailed information is displayed in two tabs, namely Overview and Advanced. The Index Overview tab looks like this:
This tab provides information in the top pane, such as on the status of the index, total number of documents present in the index, disk space used, total number of shards (primary and replicas), and unassigned shards.
The Index Overview tab also provides visualizations for Index Memory (in KB), Index size (in MB), Search rate per second, Indexing rate per second, total count of segments, and total count of documents. Shard Legend displays the status of shards belonging to the index and the information for the nodes the shards are assigned to.
The Index Advanced tab provides visualizations of other metrics, such as detailed Index Memory usage at Lucene and Elasticsearch levels, Indexing Time (in ms), Request Rate and Time, Refresh Time (in ms), Disk usage, and Segment counts: