A Semite is someone descended from Sem/Shem, one of the sons of Noah. A Hebrew is someone descended from Heber, one of the great-grandsons of Shem. So all Hebrews are Semites, but not all Semites are Hebrews. Six generations after Heber, Abraham was born to his line, so Abraham was both a Hebrew and a Semite, born of the line of Heber and Shem.
Yitschak/Isaac was born of Abraham; then Yacov/Jacob of Isaac. Yacov's name was changed to "Yshrael/Israel," and he fathered 12 sons. His sons and their descendants are called Israelites, and they would be both Semitic and Hebrew. However, this would not make either Abraham or Isaac "Israelites." Some, who interchange the words "Yew/Jew" and Israelite, call Abraham a Jew, even though Abraham was not even an Israelite, and the word "Jew" is not used in the Bible until 1,000 years after Abraham.
One of Jacob/Israel's children was Yehūdah/Judah. His descendants were called Yehudim. In Greek this reads (capital "I") Ιουδαίον Ioudaion "E-oo-day-on", from Ιουδαίοi Ioudaioi "E-oo-day-oy" . The Greek letter iota "ee-o-ta" [ Ι , ι ] was transliterated by Latin scholars as an "ee" I, and by German and English scholars of the 16th century Reformation period as representing the Germanic sound for "yot" J, as in the German word "ja" ("yah—yes"). This came down unchanged through the English vernacular translations retained in spelling as a "J" by 16th century English scholars (immersed in Latin and German scholarship), and read by ordinary non-scholars as representing the English sound for J—"JAY" .
The confusing factor is that almost all Bible translations employ the word "Jew," which is a modern, shortened form of the word "Judahite." Every time you come to the word "Jew" in the Old Testament Scriptures, you should pronounce it as "Yew", and read it as "Jūdahite", understood as "Yehūdahite"; and every time you come to the word "Jew" in the New Testament Scriptures, you should understand it as "Judean" and pronounce it as "Yūdean", which is very close to the German word "Juden", which is, of course, pronounced "Yūden", in Latin "Iūden". The same principle of pronunciation applies to all biblical spellings of Jewish names and places, especially in the Old Testament.
The descendants of Sem/Shem include Assyrians, Chaldeans, Aramaeans, Sabaeans, Arabs, and Hebrews. Modern Semitic languages include Modern Arabic, Modern Hebrew, Maltese and the Ethiopic Semitic creoles. Semitic religions include the Abrahamic religions, namely, Judaism and Christianity.