@dolliebauble both
The upper class mostly inherit their wealth, titles, etc.
The upper middle class inherit some of and earn some of their wealth, helped by their social capital
The lower middle class may inherit a little of but mostly earn their wealth,their social capital is higher than working class but not as high as the upper middle or upper classes
The upper working class are unlikely to inherit any of and will earn their wealth, despite lesser social capital which will make this harder than the middle classes
The lower working class won't inherit any wealth and will earn what they can, limited by their limited to no social capital
They are largely manual workers
The under class won't inherit or earn any wealth and have limited to no social capital.
Traditionally in one generation you could move up one class group to the next but not two. Therefore to be upper middle class, your grandparents would normally have to be upper working class at least. However, the class system has much more wriggle room than it used to. It would be impossible to go from the "bottom" to the "top" though, as essentially the upper class is still the most difficult to enter within a limited generational span.