# Use themes
A WordPress Theme is a collection of files that work together to produce a graphical interface with an underlying unifying design for a weblog. These files are called template files. A Theme modifies the way the site is displayed, without modifying the underlying software. Themes may include customized template files, image files (.jpg, .gif), style sheets (.css), custom Pages, as well as any necessary code files (.php). For an introduction to template files, see Stepping Into Templates.
You can get you theme by /content/themes after default installation,WordPress comes with three themes for you: the default Twenty Fifteen theme, and previous defaults Twenty Fourteen theme and Twenty Thirteen theme. You can switch between Themes using the Appearance admin panel. Themes that you add to the theme directory will appear in the Administration Screen > Appearance > Themes as additional selections.
# Adding New Themes
- Download or prepare a theme which has been packaged and the suffix of the package is zip
- Login to the WordPress,go to Administration Screen -> Appearance -> Themes -> Add new
- upload Themes or one Click the online themes,you can install the theme
- After installation of theme,you should active it by Administration Screen > Appearance > Themes
- From the Themes panel, roll over the Theme thumbnail image for the Theme to activate the Theme click the Activate button.
If you have any problems, it is probably related to permissions issues on the file system.
# Update Theme
You can get the update guide for theme from the theme provider,but there also have a general update method
- Backup all you data and files of WordPress site
- delete the your theme by FTP or Linux shell or Panel
- upload your theme and unzip it
- file system permission setting
- active the themes
- complete the more updating process of you theme