Update data-service.adoc (#2357)

* Update data-service.adoc
* Updates after review

---------

Co-authored-by: Simon Dew <[email protected]>

Author: nawazish-github

modules/learn/pages/services-and-indexes/services/data-service.adoc

@@ -51,7 +51,7 @@ xref:manage:manage-buckets/flush-bucket.adoc[Flush a Bucket].
 The expiry pager runs every 10 minutes by default: for information on changing the interval, see `cbepctl` xref:cli:cbepctl/set-flush_param.adoc[set flush_param].
 For more information on item-deletion and tombstones, see xref:data/expiration.adoc[Expiration].
  ** *Batch Reader*: Enhances performance by combining changes made to multiple items into _batches_, which are placed on the disk queue, to be written to disk.
-* *Scheduler*: A pool of threads, mainly purposes for handling I/O.
+* *Scheduler*: A pool of threads mainly used for handling I/O.
 The threads are divided into four kinds, which run independently of and without effect on one another:
 
  ** *Non IO*: Tasks private to the scheduler that do not require disk-access; including connection-notification, checkpoint removal, and hash-table resizing.