In this post, we'll define what a qubit is, show a few examples of how a qubit is used, and provide several ways for getting started with qubits to get a deeper understanding.
What is a qubit?
A qubit is a quantum bit, as opposed to classical bits found in classical computers. In classical systems, bits are either one or zero. Quantum systems, such as processors, can use two qubits. In binary form, these are ones and zeroes. However, in a quantum system with two qubits, these represent two universes that are also partially linked. Interestingly, the two universes are not always completely separable, and they remain partially linked even when they are not observed. This strange behavior of quantum systems leads to some interesting potential applications for qubits. For example, qubits can be used to create unbreakable codes, as well as incredibly powerful computers.
What are some potential applications for qubits?
As mentioned above, qubits can be used to create unbreakable codes. In addition, qubits can be used to create incredibly powerful computers. Quantum computers are able to solve problems that classical computers cannot, due to the way that quantum systems behave. For example, a quantum computer could be used to factor large numbers, which is important for security purposes. In addition, quantum computers can be used to simulate other quantum systems, which could lead to advances in physics and chemistry.
How are qubits used?
Qubits can be used for a variety of different tasks. One of the most common applications is quantum computing. In a quantum computer, qubits are used to store information. However, unlike classical computers, quantum computers can exploit the strange behavior of qubits to perform calculations incredibly quickly. This makes them potentially useful for a variety of tasks, such as solving complex mathematical problems or searching large databases. Other potential applications for qubits include creating unbreakable codes and developing new sensors.
Are there any limitations to qubits?
One of the biggest challenges facing quantum computing is scale. In order to create a quantum computer that is powerful enough to be useful, it would need to contain a large number of qubits. However, as the number of qubits increases, so does the chance of errors occurring. This is because qubits are very delicate and are easily disturbed by outside influences. As a result, keeping a large number of qubits stable enough to perform calculations is a major challenge.
How can I get started with qubits?
If you're interested in learning more about qubits, there are a few different ways to get started. One option is to read about quantum computing and its potential applications. Alternatively, you could try using a quantum computer simulator to get a feel for how they work. Finally, if you're feeling ambitious, you could try building your own quantum computer. However, this is a very difficult task and is only suitable for experienced physicists.
Types of qubits

Trapped ion qubits
What is a trapped ion qubit? A trapped ion qubit is a quantum bit that is stored in an ion trap. Ion traps are devices that use electric fields to hold ions in place. Trapped ion qubits are some of the most stable qubits, which makes them ideal for quantum computing. However, they are difficult to scale up and so far have only been used to create small quantum computers. 
Superconducting qubits
What is a superconducting qubit? A superconducting qubit is a quantum bit that is stored in a superconducting circuit. Superconducting circuits are made from materials that conducting electricity with no resistance. They are very stable and can be scaled up to create large quantum computers. However, they require very low temperatures to work properly, which can be difficult to achieve. 
Neutral atom qubits
What is a neutral atom qubit? A neutral atom qubit is a quantum bit that is stored in a cloud of ultracold atoms. Ultracold atoms are atoms that have been cooled to near absolute zero. Neutral atom qubits are very stable, but they are difficult to scale up. 
Quantum dot qubits
What is a quantum dot qubit? A quantum dot qubit is a quantum bit that is stored in a semiconductor nanostructure. Quantum dots are tiny structures that can confine electrons in three dimensions. Quantum dot qubits are very stable, but they are difficult to scale up. 
Topological qubits
What is a topological qubit? A topological qubit is a quantum bit that is stored in a topological quantum state. Topological quantum states are very resistant to outside influences, which makes them ideal for quantum computing. However, they are difficult to create and have only been observed in a few experiments. 
Photonic qubits
What is a photonic qubit? A photonic qubit is a quantum bit that is stored in a single photon. Photonic qubits are very stable, but they are difficult to scale up.
What are the benefits of qubits?
 Qubits are very versatile and can be used for a wide range of tasks
 Qubits are very stable, which makes them ideal for quantum computing
 Qubits are resistant to outside influences, which makes them ideal for creating unbreakable codes
Examples of qubits
 Qubits can be used to create unbreakable codes
 Qubits can be used to create incredibly powerful computers
 Qubits can be used to simulate other quantum systems
 Qubits can be used to factor large numbers
 Qubits can be used to search large databases incredibly quickly
 Qubits can be used to create powerful new drugs
 Qubits can be used to create incredibly accurate clocks
 Qubits can be used to study quantum gravity.
As you can see, qubits have a wide range of potential applications. They are an incredibly versatile tool that could revolutionize many different fields.
Conclusion
In conclusion, qubits are quantum bits that can be used for a variety of tasks, such as quantum computing and creating unbreakable codes. They are limited by their fragility and the difficulty of keeping a large number of them stable. However, they have the potential to be incredibly powerful and could revolutionize computing as we know it.
Resources
 What is a Qubit?  Microsoft Azure  Get an introduction to qubits and how they work, including the difference between qubits and binary bits and how qubits provide the foundation for quantum computing. (azure.microsoft.com)
 What is a qubit?  Repository containing the frontend of the Quantum Inspire project. The projects consists of an inbrowser editor that allows the user to write and run/simulate quantum algorithms written in QASM. Also, users can access information about quantum comp (quantuminspire.com)
 Qubit  Wikipedia (en.wikipedia.org)
 What is a qubit?  Institute for Quantum Computing  From Bits to Qubits (uwaterloo.ca)
 What is qubit?  Definition from WhatIs.com  A qubit is a quantum bit, the counterpart in quantum computing to the binary digit or bit of classical computing. Just as a bit is the basic unit of information in a classical computer, a qubit is the basic unit of information in a quantum computer. (techtarget.com)
 The qubit  IBM Quantum  Learning, howto, and reference materials for IBM Quantum (quantumcomputing.ibm.com)
 What Is a Qubit?. Lecture 2 of Introduction to Quantum…  by Chris Ferrie  The Startup  Medium  Welcome to Introduction to Quantum Computing. I am your guide, Associate Professor Chris Ferrie, a researcher in the UTS Centre for Quantum Software and Information. This is Lecture 2. It would… (medium.com)
 What is a Quantum Bit (Qubit)?  Definition from Techopedia  This definition explains the meaning of Quantum Bit and why it matters. (techopedia.com)
 Explainer: What is a quantum computer?  MIT Technology Review  This is the first in a series of explainers on quantum technology. The other two are on quantum communication and postquantum cryptography. A quantum computer harnesses some of the almostmystical phenomena of quantum mechanics to deliver huge leaps (technologyreview.com)
 7 Things You Need To Know About Qubits  Strangeworks (quantumcomputing.com)
 Quantum for dummies: the basics explained  E&T Magazine  Professor Alan Woodward from the University of Surrey attempts to demystify the quantum world by explaining key terminology and theory. (eandt.theiet.org)