I often ask myself this question and I have used it as a journal prompt many times in the past. There are so many ways to define a home.
There is the house where I grew up. I lived there with my parents and my sister until I was thirteen years old. I have many memories associated with that house, yard, street, village. It felt like home at one time. Now when I visit, I feel like a stranger; everything has changed so much.
I often talk about Ireland as my home. I lived in Ireland for the first thirteen years of my life. I can still visit my granddad's house and feel like nothing has changed. It still feels like a home. When I visit I feel like I am going home, but when I leave I am also going home. Confusing.
Then there is the house where my parents live. I never lived there. I had already moved out before they bought it, but there is something about the house where your parents live that feels like home. Everything feels so familiar, so homey.
Now I have my own home. My husband and I bought a beautiful historic house, and we have filled it with our familiar, homey stuff. I can't imagine ever living anywhere else, although it is entirely possible that my life will take me somewhere else.