Page 200 of the DMG states:
If the spell is on your class's spell list you can use an action to read the scroll and cast its spell.
So if a wizard were to pick up a spell scroll containing a wizard spell, the wizard would be able to identify it.
Later in the same paragraph it also states:
Otherwise, the scroll is unintelligible.
So if the wizard were to pick up a sorcerer spell,the wizard wouldn't be able to read it.
In conclusion if the spell is on the reader's spell list then the reader would be able to identify it.
###Casting spells of levels the spellcaster doesn't have
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Casting spells of levels the spellcaster doesn't have
Page 200 of the DMG again:
If the spell is on your class's spell list but of a higher level than you can normally cast, you must make an ability check using your spellcasting ability to determine whether you cast it successfully. The DC equals 10 + the spell's level. On a failed check, the spell disappears from the scroll with no other effect.
So for example: If you have a 2nd level wizard who finds a spell scroll containing the spell fireball, the wizard can cast if it can pass an INT check of 13 otherwise it has no effect.