What is Bloch Sphere?

What is Bloch Sphere?

Bloch Sphere is a representation of Qubit. The probability amplitudes for the superposition state,  are given by ${\displaystyle \alpha =\cos \left({\frac {\theta }{2}}\right)}$ and ${\displaystyle \beta =e^{i\phi }\sin \left({\frac {\theta }{2}}\right)}$