Here is a quick Bible lesson on something potentially confusing, but I do a lot of editing and review for Bible teachers, and it seems this might be helpful to a lot of people to see this written concisely:
The Hebrew word “YHWH” is the name of God which means something to the effect of “I am who I am” and was *copied* that is *written* (not pronounced) as “Jehova” but always *pronounced* “Adonai” (meaning sir or Lord) and translated in English to “LORD” with caps. Otherwise “Lord” (lowercase o r d) means master, or sir, but which also is used to refer to God, especially in the New Testament where it almost always refers to Jesus Christ, the Lord (Greek, “kurios” sir, master) linking Jesus to the LORD God.
“no one can say “Jesus is Lord” except in the Holy Spirit.” (1 Corinthians 12:3)
“in your hearts honor Christ the Lord as holy always being prepared to make a defense to anyone who asks you for a reason for the hope that is in you” (1 Peter 3:15)
“if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved.” (Romans 10:9)