Twilight is usually associated with evening time and this is why there is some confusion about dusk and twilight. Some people will say that the sun has set and so it is twilight, others will say that the sun has set and so it is dusk. Technically both are right (possibly).
In reality twilight can actually be either morning or evening, but it is the light which is in the sky when the sun is below the horizon, both as the sun rises and the sun sets.
Dusk is a period (again both in the morning and at night) when twilight is at its gloomiest, in other words at its darkest stage before light appears (morning) or the sky goes fully dark (evening).
Usually we talk about dusk and twilight as being in the evening, since for many people, particularly in the summer months, they do not see the sun rise, only the setting of the sun.
In reality twilight can actually be either morning or evening, but it is the light which is in the sky when the sun is below the horizon, both as the sun rises and the sun sets.
Dusk is a period (again both in the morning and at night) when twilight is at its gloomiest, in other words at its darkest stage before light appears (morning) or the sky goes fully dark (evening).
Usually we talk about dusk and twilight as being in the evening, since for many people, particularly in the summer months, they do not see the sun rise, only the setting of the sun.