After I compared Encarta encyclopedia with Britannica encyclopedia, I found that:

For Encarta encyclopedia:

 The website is not reliable, it allows everyone to edit it.

  It doesn’t show the author information.

  It doesn’t have any picture.
  Has reference list.

For Britannica encyclopedia:

It provides the author’s name

Public people are not allowed to edit it.

It has the picture of the character.

Does not have reference list.

The similar of two types encyclopeida
- have clear headline
- access through online
- have contents
- use formal language