The Two Charges
The House of Representatives voted to impeach President Clinton on two charges. The first charge was perjury, which means Clinton was accused of lying under oath when he testified before a grand jury in August 1998. The second charge was obstruction of justice, meaning he was accused of trying to prevent the truth from coming out and interfering with the legal investigation.
What Started the Investigation
Independent Counsel Kenneth Starr investigated Clinton's relationship with Monica Lewinsky, a White House intern. During his testimony, Clinton initially denied the relationship under oath. Later evidence proved the relationship had occurred, leading to charges that Clinton had lied and tried to cover it up.
The Impeachment Vote
On December 19, 1998, the House of Representatives voted to impeach Clinton. The vote was largely along party lines, with Republicans voting in favor and Democrats voting against. Impeachment means the House formally charged the president with wrongdoing, but it does not remove him from office.
Senate Trial and Acquittal
After impeachment, the case went to the Senate for trial in January 1999. To remove Clinton from office, two-thirds of the Senate (67 votes) would have needed to vote guilty on at least one charge. Neither charge received enough votes. The perjury charge received 45 guilty votes, and the obstruction of justice charge received 50 guilty votes, both falling short of the 67 needed.
Significance
Clinton remained in office and completed his second term as president, which ended in January 2001. This was only the second presidential impeachment in American history, after Andrew Johnson in 1868. 
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