HTML has three main list types: ordered, unordered and description lists.
An ordered list, <ol>, numbers its items because their sequence matters, as in recipe steps.
An unordered list, <ul>, shows bullets for items whose order doesn't matter.
A description list, <dl>, pairs terms in <dt> with descriptions in <dd>, for glossaries or key-value metadata.
Items in <ol> and <ul> go in <li> elements. To choose between them, reorder the items in your head. If the meaning changes, use <ol>. Its start and reversed attributes control the numbering.
Rewriting in plainer words…
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