margin

inline <span>

margin:auto; width:100px margin:auto; width:100px

margin:50px margin:50px

margin:10% margin:10%

inline-block <span>

margin:auto; width:100px margin:auto; width:100px

margin:50px; width:100px margin:50px; width:100px

margin:10%; width:100px margin:10%; width:100px

inline-block <div>

margin:auto; width:100px
margin:auto; width:100px

margin:50px; width:100px
margin:50px; width:100px

margin:10%; width:100px
margin:10%; width:100px

block <div>

margin:auto
margin:auto

margin:50px
margin:50px

margin:10%
margin:10%

margin:50px auto; width:100px
margin:50px auto; width:100px
CSS Practice