Shiva means being in the home of the deceased for seven days of mourning. The house is open to anyone who wants to visit and give condolences. Paying a visit to a Shiva is considered to be a "mizvah", a good deed.
I am not Jewish and when I first came to Israel many years ago, I found this tradition very strange. I could not understand why people would be content with many callers every day. I thought mourning to be something very individual and private and that I would like to be alone with my tears and sorrow and despair after losing someone beloved. I could not see how this could be shared with so many so short after the sad event. I changed my opinion completely. I attended many funerals here, and paid my respect at the Shivas that followed. I noticed to my astonishment how comforting this always was for the mourners and how it gave them an opportunity to start dealing with their grief. The different ethnic groups have individual practices, regarding for example prayers and refreshments and food for themselves and the visitors. But there are fundamental rules of how to practice the Shiva for all people of Jewish faith. Sitting Shiva is indispensable for the nearest relatives, which means parents, son, daughter, siblings and spouses. The Shiva lasts for seven days, during which the family members gather in the home of the deceased, but the Shiva can be held at other locations too. There are many rules and restrictions. Have a look about them at Wikipedia.
No one in my husbands family is religious and the rules are not strictly enforced. But the sitting of the Shiva takes place. It was held in my father-in-law's home.
My parents-in-law arrived from Irak 1950, two years after the State of Israel was established. They started building a life and like any other newcomers encountered many hardships. There are a lot of stories to tell, and at our Shiva they got told. Many memories of my mother-in-law surfaced, and her husband, who was heartbroken by her loss, slowly calmed down. He got engulfed in the stories, especially those from Baghdad, and he even contributed to them, and within his cries there were smiles and even laughter. We put photo albums on the table and people loved to look at the pictures from old times and many had to add their own anecdote to them, spinning a yarn of events that span from Irak to Israel. This was all very dear and comforting, and interesting. I never tire of the tales of my husband's family and I heard some I still did not know. A Shiva can be an opportunity to bring the family closer together, to get hugs from friends and comforting and soothing words. My mother-in-law was very old and her time had come. But I attended Shivas of much more heartbreaking deaths - and still I got to see the same momentary wonderful results of the consolation the visitors gave to the mourners.
The seven days of Shiva for my mother-in-law are over. Her name was Tikva, which means hope, and it is not only my hope, but I know that she will be remembered and mentioned and talked about by all of us very often. Rest in peace Tikva!