apachectl和httpd有什么区别？
apachectl是httpd上的设置环境的包装类。
英文参考
apachectl is a wrapper over httpd and just sets some environment variables and adds further functionality, like configtest, more in detail here. httpd.worker is like httpd but with the worker module enabled.
The first script executes the httpd.worker binary with the httpd.conf configuration file.
Correct, apachectl appends the -k start parameter to httpd