While both mean the name has been used previously in their lineage, a junior (Jr.) means the child is named after a parent, while "the second" (II) indicates the exact same name was used previously by someone in the family, such as a grandparent or cousin..
Also, can you use II instead of JR?
When it comes to the II suffix, it is traditionally used when naming a child (usually a boy) after a male family member other than the father. While it would be perfectly acceptable today to call a boy named after his father II instead of Jr, this was not so in the generations of our ancestors.
Furthermore, what comes after Sr and Jr? A man with the same name as his father uses “Jr.” after his name as long as his father is alive. His father may use the suffix “Sr.” for “senior.” The son may either drop the suffix after his father's death or, if he prefers, retain it so that he won't be confused with his late father.
In respect to this, can my son still be a junior with different middle name?
From Behind the Name: "Junior is used to distinguish a son with the same name as his father. The Junior must be a son of the father, not a grandson. The names must be exactly the same, including the middle name. The father must still be living.
Are you still a JR If the Sr died?
The only person who is supposed to be called, "Junior" is the son of someone with the exact same name. Once his father dies, he is no longer a "Junior". If the former, "Junior" does have a son of the same name he beomes "Senior" and his son moves up from "III" to "Junior".
Related Question Answers
What do you call JR SR III?
Someone can use both the “Sr.” or “Jr.” suffix and/or a Roman numeral suffix if they so wish. If our Barnabas Ludwig Johnson II below and his son, Barnabas Ludwig Johnson III, are both still alive, then the former can be called “II” and/or “Sr.”, while the latter can be called “III” and/or “Jr.”How do you write Jr with initials?
In common writing, you would be A. B. C., Jr. Initials are usually given with a period after, and then, the name or initials are separated from any titles with a comma.What is the order of SR Jr III?
Someone can use both the “Sr.” or “Jr.” suffix and/or a Roman numeral suffix if they so wish. If our Barnabas Ludwig Johnson II below and his son, Barnabas Ludwig Johnson III, are both still alive, then the former can be called “II” and/or “Sr.”, while the latter can be called “III” and/or “Jr.”Where do you put the suffix in a name?
In a full name listing, the suffix follows the last name because the person is primarily known by is given name and surname, the suffix being a secondary piece of information. When listing last name first, the given name follows the surname because that is how we sort: all the Does, then the Johns, and finally the Jr.Is JR a suffix?
In the United States the most common name suffixes are senior and junior, which are written with a capital first letter (Sr. and Jr.) with or without an interceding comma.What comes after JR in a name?
A man with the same name as his father uses “Jr.” after his name as long as his father is alive. When a man is named after his father who is a “Jr.,” he is called “the third,” once written with either the numeric 3rd or the Roman numeral III, but now the latter is used almost exclusively.Where does Jr go when last name first?
Generational titles such as Jr and Sr would make the most sense to have placed at the end of the name, regardless of first/last name order. It is still a suffix, and supposed to be the last point of the name.Is Miss a suffix?
Well, in the context of personal information you have a prefix (Mr., Miss., Mrs., Ms., Dr.), and you might also have a suffix (Sr., Jr., II, III). This is called a "name suffix" or "nomenclature suffix" -- a style at the end of a person's name giving additional identifying information about the person.What happens when a JR has a son?
Summary: Both are used to identify that the person is the second in the family to have the name. Jr is used when the son has the same name as the father. The second (II) is used when the elder family member is anyone other than the father.Can a JR skip a generation?
There's no “on a break” of suffix-naming: it's the firstborn son of each name-holder, and there is no skipping. And we know that we don't get to go back into our family trees and pick up the suffixes from where they left off several generations ago: we'd need to start a new line.Is Junior a middle name?
The terms Jr. and II can both be correctly used if a child's first, middle, and last names are identical to his or her parent's names. Jr. or II can be used when being named after the father, however they are both pronounced differently; Jr. is pronounced as junior and II is pronounced as the second.Is it OK to name your second son JR?
Unequivocably, yes -- to the question of whether a junior can be the second, third, or fourth son. The "junior" in the family is whichever boy is given the same name as his father. Although it is commonly the firstborn son, it is not always the first, and it is just as valid if it is the tenth son.Can I name my son the second instead of junior?
Both are used to identify that the person is the second in the family to have the name. Jr is used when the son has the same name as the father. The second (II) is used when the elder family member is anyone other than the father.Is JR Part of last name?
The suffix is an explanation of the first name, not the last. "John Doe Jr." means he is John, the son of John. In a full name listing, the suffix follows the last name because the person is primarily known by is given name and surname, the suffix being a secondary piece of information.What is Jr Sr III IV?
For suffix on birth certificate 1st generation — no suffix. 2nd generation — Jr. is born, and 1st generation becomes Sr. 3rd generation — III is born. 4th generation — IV is born.Does a junior have to be first born?
The "junior" in the family is whichever boy is given the same name as his father. Although it is commonly the firstborn son, it is not always the first, and it is just as valid if it is the tenth son.Is JR a suffix or prefix?
Someone can use both the “Sr.” or “Jr.” suffix and/or a Roman numeral suffix if they so wish. If our Barnabas Ludwig Johnson II below and his son, Barnabas Ludwig Johnson III, are both still alive, then the former can be called “II” and/or “Sr.”, while the latter can be called “III” and/or “Jr.”What does JR SR III mean?
Someone can use both the “Sr.” or “Jr.” suffix and/or a Roman numeral suffix if they so wish. If our Barnabas Ludwig Johnson II below and his son, Barnabas Ludwig Johnson III, are both still alive, then the former can be called “II” and/or “Sr.”, while the latter can be called “III” and/or “Jr.”Does JR mean the second?
While both mean the name has been used previously in their lineage, a junior (Jr.) means the child is named after a parent, while "the second" (II) indicates the exact same name was used previously by someone in the family, such as a grandparent or cousin. These suffixes are not just for men, women can also be Jr. 
