Urdu is a very specific language when it comes to words for family members. Uncles and aunties are never just that, they have different "titles" depending on if they are maternal or paternal relatives, and also if they are older or younger. To make it even more confusing nicknames are commonly thrown in to the mix!
For example, your paternal grandfather and grandmother are"dada"and "dadi", but your maternal grandfather and grandmother are "nana" and "nani" Your maternal uncles would all be "mama(or mamu)", and maternal aunts would be "khala", but your paternal uncles older than your father would be "tai abu" and the uncles younger than your father are "chacha(or chachu)", your paternal aunts would be "pupo".
Daughters in law are "Bahu", and are called "babhi" by all brothers and sisters, but other bahus may refer to each other differently. If the other bahu is married to your husband's older brother than she is your "jaytani"(and your husband's elder brother would be your "jayt"), if she is married to your younger brother then she is your devarani(and your husband's younger brother would be your "devar").
It can be a bit confusing having so many names for people, but it does save time when referring to someone you can just say for example- "she is my jaytani", instead of saying "she is the wife of my husband's elder brother" or "he is my chachu", instead of "he is my paternal uncle who is younger than my father". It did take a while to memorize all the different words, but it does help when the family is talking about extended family, I know who's who!
Nicknames are also common in our family. Actual names are only used by people older than you, and a lot of the time even then a nick name is used. Tariq has five sisters, each has a nickname, the oldest is "baji"(respectful title for your older sister), the second is "appi"(another respectful term for an older sister) then there is billi(cat), janu(like sweetheart, all the children call her this), and chanda(moon). The eldest son(my jayt-BIL older than Tariq), is called "Bhai" by everyone except my father in law who uses his name. Tariq is called "Tariq Bhai"(never just his name, for respect), by all except his father and older brother, and I. I call him something totally different. If we are alone I might call him by his name or an endearment like "honey", or "babe". If we're in front of his younger family I might still use his name, but no endearments! If we are out of the house or in the presence of older relatives I use what a lot of women call their husband "soon-yeh", which just means "listen". The Gori Wife had a great post on this whole topic(the names/titles and the not saying the husband's name thing) awhile ago-here it is.
I have my actual name as is listed on my IDs(only my own family and some friends use this, and Tariq when he is trying to be funny), and then the name I used after my reversion, Aishah which is used by all my in laws and some friends. But there is a distinction- all the people older than me in the family(Father in law, brother in law, his wife and two older sisters in law) call me Aishah, but the younger ones(three sisters in law and other younger cousins) never say just my name but always-"Aishah Babhi". One of Tariq's cousin's wives calls me the "dulhan"(bride), I think it is very sweet.
The nicknames and different titles are an interesting way of showing respect within the family.
For reference if any one is interested
Maternal grandparents-Nana, and Nani
Paternal grandparents-Dada and Dadi
Maternal uncles, and their wives-Mamu and Mami
Maternal aunts and their husbands-Khala and Khalu
Paternal uncles older than your father and their wives-tye abu and tya
Paternal uncles younger than your father and their wives-chachu and chachi
Father-Abu(there is another word, but it is not common-baap)
Nephews and Nieces(brother's side)-Bateeja and bateeji
Nephews and Nieces(sister's side)Bahenja and bahenji
Husband's sister and her husband-Nund and Nundoy(although this one is really old fashioned and no one actually uses it)
Husband's brother and his wife(older than your husband)-Jayt and jaytani
Husband's brother and his wife(younger than your husband)-Devar and devarani
Father in law and Mother in Law-Sussar and Saas(most people just use the title their husband/wife uses-like ami and papa)