You can use it to access information about your surroundings, such as maps, directions, and news.
You can use it to communicate with other characters, either through voice or text.
You can use it to access your character's inventory and equipment, allowing you to quickly select and use items without the need to physically retrieve them from a bag or pocket.
You can use it to hack into computer systems, either to gather information or to manipulate them for your own purposes.
You can use it to scan for electronic devices, such as security cameras or automated turrets, and either disable them or use them to your advantage.
A few examples: