Did you see big systems implementations?
Did you participated in a system implementation or deployment?
What is your current role?
What is your carrier goal?
Every company is organised in a different way. Every company is build in a different way. But it all starts from a vision that is going to be mapped into an architecture. Once the concept or the first sketches of the architecture are established the implementation process is going to follow.
It is an example how it can look like. If you are interested in other options it is worth to take a look at some of the established (enterprise) architecture frameworks. Generally speaking, it is rather a quite difficult document to read as it tries to address the issue of an enterprise company. But even though its complexities it still gives a good overview how complex some processes, implementations or deployments can be. Below is a table from FEAF framework that list key roles and teams for an organisation.
This one below shows the concept of an architecture from a high level point of view.
The more detailed description of the architecture domains can be found here. Personally, I'm specializing in the area of technical infrastructure architecture. With the specialization in virtual networking and cloud network in IaaS cloud.
Technical architecture or infrastructure architecture: The structure and behaviour of the technology infrastructure. Covers the client and server nodes of the hardware configuration, the infrastructure applications that run on them, the infrastructure services they offer to applications, the protocols and networks that connect applications and nodes.