In computer Networking there are a various tracks. There are some common one.

1. Routing and Switching (R&S): 

Routing and switching are used for the connectivity. Connecting to devices and to share the resorces or information we are doing routing and switching and using router and switch.
The most popular vendor course is cisco CCNA (R & S).
The current CCNA version is 200-301. If you want to start the carrier in IT networking, please go with CCNA.





ROUTER





2. Voice over IP: 

We use IP phones that are connected to the network and a digital telephony system with
calling rules. We also have to make sure that voice traffic gets preference on the network
or you end up with poor audio quality.

Initially, Computer networks were constructed exclusively for information traffic and we utilized telephone links for communication. These days, we additionally utilize similar information network for communication with VoIP
(Voice over IP).

IP PHONE


3. Wireless:

In the no so distant past, most organizations just had PCs with wired associations.
These days, a ton of clients enter the office with a PC, cell phone, and tablet,
anticipating network for this large number of gadgets. Remote systems administration implies you need to comprehend how information is sent and gotten utilizing radio waves and how to construct a
network that upholds many remote clients utilizing equipment like passageways and
remote regulators.
Nowadays, wireless network is very popular. Wireless users using hardware like access point and wireless controller. 
Wireless controller is device through which we can centralize manage the access points.
Access Point

4. Data Center: 

A data is a facility that in managing the thousands of servers and networking devices. Data center is centralized location of an organization's from where managing IT operations and devices to storing the data and application of the organization and users.
The requirement of the networking devices in the data center is depends on the requirements of the an organization and how big it is.
Data center of any organization is very critical location or part of the organization.

5. Network Security:

Network security is a set of technologies that protects the usability and integrity of a company's infrastructure by preventing the entry or proliferation within a network of a wide variety of potential threats.