How do I securely give access to external users inside my Cyn.in site

Yes, The correct way would be to create space for each customer and manage content inside using categories. Follow the steps below if you are required to provide your customers an work area in your site for collaboration.

Securing your Main space from customer edits. 

1. Login in to your cyn.in site using site administrator rights 
2. Click on sharing tab, UnSelect "Inherit permissions from higher levels" 
3. Click on Save
4. Unselect "Can Add" for "Logged-in" users
5. Click on Save

Creating a group for your customer. (this is required if your customers requires multiple logins in the collaboration area for all customer contact persons)

1. Login in to your cyn.in site using site administrator rights
2. Click on Manage Menu icon in the topbar (Hint: next to help icon)
3. Click on Group Management option, you will be presented with groups overview page 
4. Click on "Add New Group", Fill in the groups details
5. Click "Save"

Creating a space for your customer

1. Click on New Menu Button in the topbar (Hint: Big Green +) and choose Space
2. "Add Space" options are presented, Fill in the Space details
3. Click Save, You will be directed inside the newly created space.

Securing your newly created Customer space to allow only members of customer group to access content in the Space. 

1. Click on sharing tab in your new created space.
2. Search for the newly created customer group.
3. Select options "Can Add" "Can Edit" and "Can View" against the Customer group.
4. UnSelect "Inherit permissions from higher levels" and Unselect "Can Add" and "Can View" for "Logged-in" users
5. Click on Save.

Creating a user for your customer.

1. Click on Manage Menu icon in the topbar (Hint: next to help icon)
2. Click on User Management option, you will be presented with USers overview page 
3. Click on "Add New User", Fill in the user details (Please Note: Registering users sends an email inviting user to activate their account on the cyn.in site and set their respective passwords)
4. Click "Save"

Assigning customer user to the customer group

1. Click on Manage Menu icon in the topbar (Hint: next to help icon)
2. Click on User Management option, you will be presented with Users overview page.
3. Search for the newly created customer user.
4. Click on the user name of the customer user, you will be presented with user properties for the customer user.
5. Click on group memeberships tab (Hint: Next to user properties tab)
6. Search for the newly created customer group.
7. Select option for the customer user group.
8. Click on "Add user to selected groups"

When the customer user set his/her password and logs in to the site for the first time, the customer user will have access rights to contribute ONLY in the space the customer user has been given permissions.