Re: Child theme
Child themes work like this: Say you have a house and you want it to look different, you would then buy paint and furniture and curtains to make it loo different but the walls and roof and floors still look he same and are in the same place. The parent theme is the walls and floors and those never change.
Basically the child theme is a way to tell word press to use all the files from a theme but make certain changes you want in a separate theme that way the parent theme files are never changed. If you do need to change one of the parent files then you copy that file over to the child folder and it will override the parent file.
header.php in a child theme folder will override header.php in the parent theme folder. Make a mistake? No biggie you can just copy the parent header.php over to the child theme again since you never edit the parent files.