I think people just use the terms slightly differently. Even the Wikipedia article you linked contradicts itself.
> Sharding goes beyond this. It partitions the problematic table(s) in the same way, but it does this across potentially multiple instances of the schema.
"Beyond this" but still "potentially across multiple instances". Anyway, with your framing sharding kind of becomes "distributed horizontal partitioning".
> Sharding goes beyond this. It partitions the problematic table(s) in the same way, but it does this across potentially multiple instances of the schema.
"Beyond this" but still "potentially across multiple instances". Anyway, with your framing sharding kind of becomes "distributed horizontal partitioning".