Which technology allows developers to easily deploy applications across different environments?

Containers are a technology that allows developers to package applications along with their dependencies in a consistent environment. This packaging ensures that the application will run the same way on any system that supports the container technology, regardless of underlying differences in the host operating system or other configuration aspects.

By isolating the application from the environment specifics, containers greatly simplify the deployment process. They ensure that the developer's environment, staging environment, and production environment all operate consistently, reducing the "it works on my machine" problem that often arises in software development.

In contrast, while virtual machines also provide a form of environment isolation, they are generally heavier and require more resources since they virtualize entire operating systems. Hypervisors are used to create and manage virtual machines but do not directly relate to the simplicity and portability that containers offer. Load balancers distribute network traffic across multiple servers to ensure reliability and availability, but they do not facilitate application deployment across environments.