MySQL tables/databases into different disks I am aware that there is a possibility to have a single database server with many tables/databases, and you can separate some of those tables/databases into separate disks.
Lets say you have 5 tables/databases, and 5 drives. So you attach each table/database for a different drive. Thus increasing IO and everything else.

What is that technique called ?

I think if you try separating databases, you just mount different drive to different folder for different database, but what if you want to separate tables into separate drives (each table in different disk)
I'm not aware of a specific term for this practice but you can specify different data and/or index dirs using the create table syntax.

This only works for MyISAM tables and your OS must support symlinks.

In my practice though, we generally just segment sets databases into their own LV. These are generally a segment per functional application.  Having a single logical volume with all the tables actually in there it's easier to keep track of an manage disk space for each DB.

Those LVs though, are generally in a RAID 10 config to help balance IO.