Heroku is a cloud-based platform-as-a-service (PaaS) that simplifies the deployment, management, and scaling of applications. Initially launched in 2007, it primarily supported Ruby but has since expanded to accommodate various programming languages, including Python, Java, and PHP. Heroku allows developers to focus on building applications without worrying about the underlying infrastructure. It utilizes container-based technology, known as “dynos,” to provide scalability and flexibility. With both free and paid tiers, Heroku is accessible for developers at different stages, making it a popular choice for startups and established businesses alike.