# Global Variables

Global variables are environment settings that are set at the project level. This feature allows to define global constants and secrets (encrypted values such as passwords) that can be used in flow node [expressions ](flows/expressions)or as configuration parameters in [connectors](connectors).

The initial values of global variables are set by project developers in the project development environment. However, during the deployment of the project to different environments, administrators can override these variables with new values, as applicable to that environment.&#x20;

For example, each environment can have a different value for a database URL and password parameters. The connector that was configured in the project does not need to know upfront what the values are, and does not care if they change. This allows to generate a project deployment only once and have it deployed as the same exact immutable package to testing and production environments.

### Global Variable Types

There are two types of environment parameters that can be set through this mechanism:

* **Variables** — parameters that are set at the project level and can be seen in clear text. For those variables that have "Accessible in flows" flag set by project developers, their values are freely accessible in expressions defined in any flow node.
* **Passwords** — encrypted parameters that are not shown in clear text on the screen for security purposes, and are only shared with connectors by being referenced by name from their configuration parameters that specifically require a password. During execution, the variable names are replaced with actual password values set for that environment.
