Containers overview

Traditionally, software applications were developed following a monolithic architecture approach, meaning all the services or components were locked to each other. You could not take out a part and replace it with something else. That approach changed over time and became the N-tier approach. The N-tier application approach is one step forward in container and microservices architecture.  

The major drawbacks of the monolith architecture were its lack of reliability, scalability, and high availability. It was really hard to scale monolith applications due to their nature. The reliability of these applications was also questionable because you could rarely easily operate and upgrade these applications without any downtime. There was no way you could efficiently scale out monolith applications, meaning you could not just add another one, five, or ten applications back to back and let them coexist with each other.

We had monolith applications in the past, but then people and companies started thinking about application scalability, security, reliability, and high availability (HA). And that is what created N-tier design. The N-tier design is a standard application design like 3-tier web applications where we have a web tier, application tier, and database backend. It's pretty standard. Now it is all evolving into microservices. Why do we need them? The short answer is for better numbers. It's cheaper, much more scalable, and secure. Containerized applications bring you to a whole new level and this is where you can benefit from automation and DevOps.