Salvation is the deliverance by God of a sinner from His own righteous judgment.
God is wholly, pure, and righteous. He is the only and proper standard of righteousness in all of creation. He has revealed this standard of perfection in the Bible. We can see part of it in Exodus 20 where God gives the 10 Commandments. In these Commandments, we see the standard of moral perfection. In this moral perfection is a reflection of God's character. Jesus said, "out of the abundance of the heart, the mouth speaks," (Matt. 12:34). Therefore, we can see that as God spoke the moral law, He was giving us an insight into His own perfect and pure character. Therefore, the law is a standard of righteousness which all people are obligated to follow whether they are aware of it or not.
There is no law that is a law without a punishment for breaking that law. If a law has no punishment, then it is nothing more than a slogan. But in the case of God's law, He states that anyone who breaks it will die (Ezekiel 18:4). Therefore, the righteous judgment of God upon anyone who would break the law is that he should be damned. But God in His great mercy has provided a way out of this damnation. The provision is found only in God the Son, Jesus (John 1:1,14; 3:16; Acts 4:12), who died on the cross while He bore our sins (1 Pet. 2:24).
Therefore, we can see that salvation is deliverance of the sinner from the righteous judgment of God. Salvation means that we are "saved" from that judgment.