CSS

using overflow:hidden and clearing float

after using float:right or left doing one of these two is compulsory otherwise it may ruin your upcoming codes in the project
1)using clear:both or left or right as per your requirement==>This is used in the case when their is other elements which are not floated inside the container.The unfloated element is given the property of clear

2)using overflow:hidden==>This is used in the case if all the childs inside the parent container are floated.

Clearing floats is immportant beacause if any element is floated, then its parent donot consider it to be its child. so to sort this problem it is compulsory to clear float