An 'age' refers to the length of time that a person has lived or a distinct period in time or history. The phrase 'in this day and age' refers to 'this period of time now' or 'in this period of history'.

1. Back in my day, people on the bus would happily have a bit of a chin-wag, but in this day and age, everyone's on their phones!
2. In my day and age young people obeyed their parents and didn't question them.

1. There was a time when you could get away with underpaying employees, but in this day and age people have far more opportunities available to them, and so are less likely to put up with unfair treatment.
2. In this day and age, it doesn't make sense for most workers to come to the office every day and working remotely is preferred.

1. In this day and age, computers have become integral to how businesses operate, which is why employers across the board look for workers with at least a basic level of skill in that area.