TalkChess.com

Is a match identical to a tournament with two players?

That depends on the context. In WinBoard/XBoard there is a distinction between a 2-player tournament and an 'old-style match', although both would be a series of games between the same two players, with alternating colors.

The difference is that in a tournament progress is recorded in a 'tourney file' (*.trn), making it possible to interrupt the tourney, and restart it later. Or to run the tournament with concurrency, by starting multiple instances of WinBoard on the same tourney file. For an old-style match no non-volatile state information is kept other than any saved games, and the only way to stop it is an irreversible abort.

So what is the advantage of playing a match if tournament has more options.
Is it more efficient. Using less disk space. Or maybe less work to start a simpel match and less can go wrong.

A match is somewhat simpler to set up, as you can do it with the two engines that are currently loaded, rather than having to select participants. But mostly it is a legacy feature, which is why it is called 'old-style match'. Before WinBoard had a full-featured tournament manager integrated in it, the two-player matches were the only way to play a series of games automatically.