Four ways of using Conditional Expressions in Maximo.

Answer

Conditional UI: Allows to dynamically change the presentation elements for an application based on a combination of the security groups the user belongs to, and the conditional expression being used. For example, if the asset is a type=IT, then the labels will change to "IT Asset", and if it was another type of asset, the original label will be used instead.
This can be configured in the Application Designer application through the Configure Conditional properties button of each control properties panel.

Conditional Sigoptions: Allows to dynamically grant or revoke the user's privilege to use a security option base on a conditional expression. For example, if the asset is a type=IT, then the user cannot delete, and if it was another type of asset they can delete the asset.
This can be configured in the Security Groups application under Applications tab.
The Sigoptions are often used in conjunction with the conditional UI to further refine rules to the behavior of specific UI controls.

Global Data Restrictions: Allows to dynamically hide or make readonly/required specific objects and attributes.
This can be configured in the Security Groups application Global Data Restrictions menu action.

Group's Data Restrictions: Allows to dynamically hide or make readonly/required specific objects and attributes for a specific security group. For example, all contractors can only see Work Order for a nominated contract and staff can see all Work Orders.
This can be configured in the Security Groups application under Data Restrictions tab.