This Resolution says that, having called on North Korea to withdraw and North Korea not doing so, the UN will assist South Korea to repel the invasion by what means are necessary.
The Resolution was adopted 7 votes to 1 (Yugoslavia), with Egypt and India present but not participating in the vote and the USSR absent.
After Resolution 82 (June 25) was passed deciding that North Korea was at fault for beginning a war, the US contacted the Kremlin to use their influence to compel North Korea to comply, but the USSR denied this.
UNSC met again to discuss how to address the conflict. The resolution was for "assistance necessary" (military action). Armies were moved to South Korea.
The Security Council,
Having determined that the armed attack upon the Republic of Korea by forces from North Korea constitutes a breach of the peace,
Having called for an immediate cessation of hostilities,
Having called upon the authorities in North Korea to withdraw forthwith their armed forces to the 38th parallel,
Having noted from the report of the United Nations Commission on Korea that the authorities in North Korea have neither ceased hostilities nor withdrawn their armed forces to the 38th parallel, and that urgent military measures are required to restore international peace and security,
Having noted the appeal from the Republic of Korea to the United Nations for immediate and effective steps to secure peace and security,
Recommends that the Members of the United Nations furnish such assistance to the Republic of Korea as may be necessary to repel the armed attack and to restore international peace and security in the area.