Confusion about hybridization terminology

I was just introduced to the concept of orbital hybridization. I believe I understand the idea behind it, but there is some accompanying terminology that prevents me from achieving a greater understanding.


In the following image:


[![enter image description here](https://i.stack.imgur.com/sG43q.png)](https://i.stack.imgur.com/sG43q.png) 


I see that one of the electrons in the $2s$ orbital of carbon is promoted to one of the $2p$ orbitals. I start to get confused when hybridization occurs, simply because there are **four** $\ce{sp^3}$ hybrid orbitals, as also shown in this diagram:


[![enter image description here](https://i.stack.imgur.com/Rd47I.png)](https://i.stack.imgur.com/Rd47I.png)


I learned that the name $\ce{sp^3}$ comes from the combination of one s-orbital and three p-orbitals ($\ce{s + p + p + p}$), and this makes sense to me. What doesn't make sense is why each individual hybrid orbital is called an $\ce{sp^3}$ orbital. When the $\ce{2s}$ orbital, for example, becomes an $\ce{sp^3}$ orbital, why is it referred to by its combination with p-orbitals ($\ce{sp^3}$) when it was just an s-orbital before?


Could someone please offer a simple explanation that would help clear this up? *Why is **each individual hybrid orbital** called an $\ce{sp^3}$ orbital?* It seems like all four orbitals together should be called $\ce{sp^3}$, because they all make up the combination defined by $\ce{sp^3}$ ($\ce{s + p + p + p}$).




The number of hybridized orbitals is equal to the number of original orbitals. The name of the hybridized orbitals (e.g., $sp^{3}$) means just that the ratio of the contributions of $s$ to $p$ orbitals is $1:3$. We do not write $s^{\frac{1}{4}}p^{\frac{3}{4}}$.


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