# Shared Features in Vehicle Spy

The following features are used by many different areas in Vehicle Spy:

* [Calculated Signal Editor](https://docs.intrepidcs.com/vspy-3-documentation/shared-features-in-vehicle-spy/shared-features-calculated-signal-editor) - creates calculated values for Application Signals or Tx Panel signals.

* [DTC Database](https://docs.intrepidcs.com/vspy-3-documentation/shared-features-in-vehicle-spy/shared-features-dtc-database) - defines diagnostic trouble codes.

* [Expression Builder](https://docs.intrepidcs.com/vspy-3-documentation/shared-features-in-vehicle-spy/shared-features-expression-builder) - builds many different types of expressions used across Vehicle Spy.

* [Predefined Function Keys](https://docs.intrepidcs.com/vspy-3-documentation/shared-features-in-vehicle-spy/shared-features-predefined-function-keys) - keyboard function keys F1-F5 preassigned to Vehicle Spy tasks.

* [Starting with a Selected View](https://docs.intrepidcs.com/vspy-3-documentation/shared-features-in-vehicle-spy/shared-features-starting-with-a-selected-view) - controls which screen Vehicle Spy starts with.

* [Widgets](https://docs.intrepidcs.com/vspy-3-documentation/shared-features-in-vehicle-spy/shared-features-widgets) - programmable buttons along the window edges that can do various tasks.