Listing write steps for Core and enterprise (#5878)

Author: MeelahMe

content/shared/v3-core-get-started/_index.md

@@ -251,6 +251,22 @@ Subsequent requests can add new fields on-the-fly, but can't add new tags.
 
 {{% product-name %}} is optimized for recent data, but accepts writes from any time period. It persists that data in Parquet files for access by third-party systems for longer term historical analysis and queries. If you require longer historical queries with a compactor that optimizes data organization, consider using [InfluxDB 3 Enterprise](/influxdb3/enterprise/get-started/).
 
+#### Data persistence flow
+
+When you write data to InfluxDB 3, your data flows through the following stages:
+
+1. **Write validation**: InfluxDB validates incoming data and rejects invalid points with an HTTP 400 error.
+
+2. **Memory buffer**: Valid data points are initially stored in an in-memory write buffer.
+
+3. **WAL persistence**: Every second (by default), InfluxDB flushes the write buffer to Write-Ahead Log (WAL) files in object storage.
+   - By default, write requests are acknowledged only after this WAL persistence completes
+   - With the `no_sync` option, writes are acknowledged before WAL persistence, reducing latency but increasing risk of data loss during system failure
+
+4. **Query availability**: After WAL persistence completes, data moves to the queryable buffer where it becomes available for queries.
+
+5. **Parquet storage**: Every ten minutes (by default), InfluxDB persists data from the queryable buffer to object storage as Parquet files for long-term storage.
+
 The database provides three write API endpoints that respond to HTTP `POST` requests:
 
 #### /api/v3/write_lp endpoint