People celebrates something on day is referred to as Festival.
Christmas is most popular festival celebrate by Christian religious.
For Hindu, Diwali is most popular festival for them.
Now, Wish is good luck, hope or desire to something.
Wish is a feeling that you want to have something or that something should happen.
Nowadays people wishes and greetings to other people in many ways like Instagram, Email, Sms, Whatsapp and Phone to phone.
Its better if you directly meet and wish face to face.
Its better if you directly meet and wish face to face.