What does Buddhism teach about the start and end of world?
Here is one teaching the Buddha gave on the start of the world:


  Dwelling at Savatthi. There the Blessed One addressed the monks: "I
  will teach you the origination of the world &amp; the ending of the world.
  Listen &amp; pay close attention. I will speak."
  
  "As you say, lord," the monks responded to the Blessed One.
  
  The Blessed One said: "And what is the origination of the world?
  Dependent on the eye &amp; forms there arises eye-consciousness. The
  meeting of the three is contact. From contact as a requisite condition
  comes feeling. From feeling as a requisite condition comes craving.
  From craving as a requisite condition comes clinging/sustenance. From
  clinging/sustenance as a requisite condition comes becoming. From
  becoming as a requisite condition comes birth. From birth as a
  requisite condition, then aging &amp; death, sorrow, lamentation, pain,
  distress, &amp; despair come into play. This is the origination of the
  world.


And in the same teaching the Buddha gave the explanation for the end of the world:


  "And what is the ending of the world? Dependent on the eye &amp; forms
  there arises eye-consciousness. The meeting of the three is contact.
  From contact as a requisite condition comes feeling. From feeling as a
  requisite condition comes craving. Now, from the remainderless
  cessation &amp; fading away of that very craving comes the cessation of
  clinging/sustenance. From the cessation of clinging/sustenance comes
  the cessation of becoming. From the cessation of becoming comes the
  cessation of birth. From the cessation of birth, then aging &amp; death,
  sorrow, lamentation, pain, distress, &amp; despair all cease. Such is the
  cessation of this entire mass of stress &amp; suffering. This is the
  ending of the world.


To understand this I think takes familiarization with the Dharma and specifically the teachings on the Four Noble Truths and dependent origination.