About PHP bottom-up redemption

About the underlying implementation of PHP
What does the bottom of PHP mean by C? How is the PHP program executed at the bottom?

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Java is written in C, and PHP is written in C, just as the game is written in C + + the same nature, if you like, you can use PHP to write another language you think
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The bottom layer is really c implementation.
PHP first converted from Zend Engine to intermediate code
In the conversion from this intermediate code to C

In short, the final conversion to C

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