Spaces are where teams can communicate and access the apps necessary to them, all in one place. You can create a space with a certain group of members, and then use it to discuss relevant topics and share information.

If you have multiple topics to discuss in a space, you can add a thread for each one. Threads act as forums where space members can talk and share information with one another. By creating threads for specific topics and using them to post relevant information, you can organize the discussions that take place within a space.

For details on how to add threads to spaces, see the following page:
Adding Threads

You can also use apps to share information within a space. Apps can be added to spaces for managing things like documents, To-Do tasks, and information necessary for in-space communication.
Apps that are added to a space are referred to as "in-space apps." For details on in-space apps, see the following page:
What Is an In-Space App?

A guest space is a space that people who are not registered users of your kintone environment can join.
You can invite people from outside your organization (e.g., customers, business contacts, partners) as guests.
Guest users can view threads, make thread posts, and use in-space apps only within the guest space to which they are invited.
Having a separate space from your internal work environment allows information to be shared between companies safely and securely, without the worry of confidential information being leaked.

For more details on guest spaces, see the following page:
Guest Spaces