The Phantasy Star Online titles are a sub-series of Sega's Phantasy Star series of games that began in 1987. With the exception of Episode III, the PSO games themselves are hack and slash role-playing games where the player slays monsters, levels up, buys new equipment, etc. The online Phantasy Stars differ from the previous games of the series by offering a real-time – rather than turn-based – approach to combat, seamlessly integrating this with exploration and plot developments.
Both PS Vita and PC editions of PSO2 will use the same servers, and you can play the same character on both versions. It seems that the Andrroid versions will do the same.