You can create one-to-one or one-to-many relationship between forms in the same application or different applications. To create a relationship betweeen Form A and Form B, you have to define a field in Form B as being imported from From A.
Example: Let us take the example of an "Employee Management" application.
1. In this application a form named "Employee" is created to add each employee record. The screen-shot below shows the Employee form in "Live Mode".

2. Now, we also need to add the department details to which each employee belongs to. To do this, we will create a new form named "Department" to enter the department details in the organization. The screen-shot below shows the Department form in "Live Mode".

3. The screen-shot below shows the Department view in "Live Mode" after entering the department details to the department form.

4. Now, let us add a new lookup field "Department" to the Employee form. As shown in the screen-shot below, the "Department" field is imported from the Department form in the "Employee Managment" application.
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Note: You cannot import a picklist field as a Lookup field in another form. |

5. Now you can access the values in the Department form from the Employee form. Thus a one-to-one relationship is established between the Employee form and Department form. You can also create one-to-many relationship between forms, by importing a multi-select field.
