It is wishing and believing in something to happen or occur and is certainty someone one can have one can and may have faith in. Faith in the hope that things will get better or that the expected outcomes you are looking for will arise.
Whether or not these outcomes do occur or not, having hope inspires and motivates each of us to move on, particularly in times where despair, worry and heartache may set our surroundings. Hope helps sets our mind to want to achieve that special something, and no matter how unrealistic it may seem, in doing so, almost like setting a goal for yourself, it inspires you to continue on when you otherwise wouldn't if you didn't have hope.
While at times you may not reach or achieve a goal in all expected entriely. The process of hoping and moving towards that goal would triggered many reactions and thoughts that make the efforts worth it, much like the saying, about how 'it's about the journey, not the destination'. It's about the journey of hope, although the destination is great that will inevitably change you, and in doing so, will change the world forever as well. If not changing 'the' world, it will change 'your' world.
I would like to leave you with a quote which I hope will inspire you.
'Hope is a good thing, maybe the best of things, and no good thing ever dies' – Shawshank Redemption