Would walking or taking a walk be considered exercise?

Would walking or taking a walk be considered exercise?

I usually walk quite a bit to and from work, and I do take evening walks as well, but

You can't really consider this exercise, can you?

I'm not doing any separate strength training, so I wonder if I can lose weight with just this kind of activity....

I think I walk about 10,000 steps a day.

I walk 30 to 40 minutes to work, and I walk about the same amount for lunch.

It's the same when I get off work in the evening; I take a walk for about an hour. Would this count as exercise?