The particle "БЫ" is used in Russian when you speak about something irreal or improbable, the English equivalent is "would". This particle is also used in conditional clauses:
Я бы хотел съесть мороженое.
I would like to eat an ice cream.
Если бы я был писателем, я написал бы много книг.
If I was a writer, I would write lots of books.
Russian Language Teacher.