Column Widget is an invisible widget, it's used to control the layout of the app as the name suggests, the widgets passed into a column will get stacked on top of each other vertically similar to the shape of a column.
Column takes children as an argument which accepts a list of widgets. This list only accepts type of Widget. <Widget>[]
we use Column when we want to pass on multiple widgets to a widgets child.
In the example below, we used the column to pass on multiple widgets (text and two buttons on top of each other) to a scaffold's body.
onpressed argument is what you want to happen when the button is pressed, more on this will be covered in more detail