A Tech Stack is the combination of programming languages, frameworks, libraries, and tools used to build and run a software application. The tech stack is typically divided into two main parts: the front-end (client-side) and the back-end (server-side). The front-end stack includes technologies like HTML, CSS, and JavaScript, along with frameworks like React, Angular, or Vue.js, which handle the user interface and client-side logic. The back-end stack includes server-side languages like Python, Ruby, or Java, databases like MySQL or MongoDB, and frameworks like Django, Ruby on Rails, or Node.js, which manage the server-side logic, data storage, and business processes.

Choosing the right tech stack is crucial for the success of a project, as it impacts the development speed, scalability, and performance of the application. Factors such as the project requirements, team expertise, scalability needs, and the existing ecosystem influence the choice of a tech stack. Modern applications often leverage a mix of technologies, including cloud services, DevOps tools, and microservices architectures, to build robust, scalable, and maintainable systems. A well-chosen tech stack can provide a competitive advantage by enabling faster development, better performance, and easier maintenance.