In WordPress you are able to add content by creating Posts and Pages. Both are very similar, but serve slightly different functions.
To create a post or a page, first login to your site.
Working with Posts:
Posts make up the blog on your site. They are displayed in reverse chronological order and can be organized by tags and categories. They are dynamic and change the display of what others see on your site every time you add a new one.
Working with Pages:
Pages, although like posts have a title and content areas are different because they are static, meaning the display of the content stays the same. They are not listed by date and cannot be organized by tags or categories. You can use pages for information that is not changing on your site (like About Me, Resume, etc).