You have a trial for this game

Trials are just a small taste of the game of what you will expect. There are limits to he games depending on the game Usually all features are not allowed, also the length of the trial and period varies depending on the game

Trial versions of games are versions of the full game that will lock you out of the game/from progressing either at a certain point or after a certain time period allotted for that trial has run down. Check
this out: https://beta.support.xbox.com/help/...and-play/understanding-betas-demos-and-trials

The period for the trial depends on the game. Without knowing the game, we won't be able to tell you what period of time you can play it for/where the game will cut you off in progression. You can still
buy the full version of the game to continue to access it/progress at any point however, and you shouldn't lose any progress.

Hello be sure to check out this guide for all your questions about trials, demos, and betas.

https://beta.support.xbox.com/help/games-apps/game-setup-and-play/understanding-betas-demos-and-trials

What does it mean??

What's is the period for a terial ?

They typically rage from 24 to 48 hours.

It means that you can download it and play a trial of the game, but it won't be the full game that you own.