Difference between <ul> and <ol>

HTML-CSS
1

i know the

    is for unordering list and
    is for orderled list my question is both are for listing why cant just one be used… i dont understand please any explaination
2

an ordered list is like:

  1. a thing
  2. an other thing

you are giving an order to the items by numbering them

an unordered list doesn’t have the list items numbered, or in any specific order:

  • a thing
  • an other thing

the difference is just that

3

but in the text there was no numbering for things cat love and hate it was a bullet listing them altogether. i don’t know if i explained well ( have passed the stage if not i will have screen shot it for you to understand what am saying).

4

you write them inside the li and they get numbered automatically
you write <ol><li>a thing</li><li>an other thing</li></ol>
and you get

  1. a thing
  2. an other thing