based on the main article, 'Jehovah'
The name Jehovah is a less common vocalization of the Tetragrammaton,- from Greek τετραγράμματον, meaning "four letters" יהוה (YHWH), the proper name of the God of Israel in the Hebrew Bible which has also been transcribed as "Yehowah" or "Yahweh". 
While YHWH is the most common transliteration of the tetragrammaton in English academic studies, the alternatives YHVH, JHVH and JHWH are also used. 
יְהֹוָה appears 6,518 times in the Masoretic Text , in addition to 305 instances of יֱהֹוִה (Jehovih). The Masoretic Text was copied, edited and distributed by a group of Jews known as the Masoretes between the 7th and 10th centuries CE. The earliest available Latin text to use a vocalization similar to Jehovah dates from the 13th century and possibly earlier. 
During the 3rd to 2nd centuries BCE, the pronunciation of the Tetragrammaton came to be avoided, being substituted with Adonai ("my Lord"). 
1. Origins of the name 'Jehovah'. Wikipedia
2. The name of God in Judaism used most often in the Hebrew Bible is the four-letter name יהוה (YHWH), also known as the Tetragrammaton. El, Elohim, El Shaddai, Adonai, Elyon, and Avinu are regarded by some Jews not as names, but as titles highlighting different aspects of YHWH and the various 'roles' of God. See Names and Titles of God in Judaism (Wikipedia) for a more in depth explanation of the following names and titles of God.