Ask HN: Explain the popular data services like I am five
Part of the problem is these platforms start out with a core service but soon expand to include all sorts of stuff.<p>Snowflake&#x2F;BigQuery&#x2F;RedShift.  Think of them as databases that deal with a ton of semi structured data and are optimised to run analytics queries, typically with SQL.  These are what you build a data warehouse on, generally, though you could also use a traditional RDBMS.  Basically you collect data from all around the business and put it in one place so you can do joins or otherwise structure things in a more useful way. Imagine someone asks you to match up your Facebook ad creatives with how well those customers engage with your app using data from your own service databases.  A well-formed data warehouse makes that kind of query trivial.<p>Tableau&#x2F;Looker.  These connect to your data warehouse and act as a layer that business or other people in the company can interact with.  People who want to make charts and reports but who don’t want to or can’t write SQL, basically.  Often this is called the BI layer.<p>Data lakes are like data warehouses but less structured.  Data swamps are data lakes that are such a mess as a result that nobody wants to deal with them.<p>ETL you can just think of as a script that takes data from a source and shoves it in a destination, often from your production databases or third party services to your data warehouse.  Typically the data you get out from the source doesn’t match what it should look like in the data warehouse, so transformation is done here too.<p>Segment I haven’t used but my understanding is it saves you interacting directly with the million different places you want to send data to and receive data from.  So instead of installing (say) 10 SDKs in your mobile app and sending events individually to each, you just install Segment, send them to it, and it distributes to the others.<p>Caveat: this is all an oversimplification and flippantly described.  Feel free to ask more specific questions though.<p>I don’t really think it’s particularly out of hand.  Everything has its purpose, mostly.  You’re just at that stage where you’re on the outside and it seems impenetrable.  And each component has a few companies competing for the crown, which inflates the entities in the space, but not the number of different types of ‘things’ in there.