NoSQL is a bad name that really doesn't have anything to do with SQL per se, but is a shorthand for non-relational datastores (no one calls non-SQL relational systems “NoSQL”), which, while they depart from the relational model in a number of different ways, typically include eventual rather than strong consistency to support liveness in a distributed context.

NoSQL in some cases trades off consistency for scalability (generally by sharding data, so propagating data across shards introduces eventual consistency).

As you can imagine, data that reside in a single shard don’t need to be propagated, so you can get strong consistency easily (e.g. fetching a single document). It’s when you start doing queries, joins, aggregations, etc. that you start encountering eventual consistency.

Mainly that most people who ask that question are using it as a lead-in to promoting a NoSQL product.