PHP7 is a brand new version of the PHP programming language, which has been greatly improved mainly in terms of performance. Official documents show that PHP7 can achieve twice the performance of PHP5.x version. At the same time, the syntax of PHP is sorted out, and many popular syntax formats in other languages are provided. The commendable thing is that after making such a big change, the compatibility of PHP7 is still very good. For the vast majority of applications, you can migrate to the PHP7 version without making any modifications.