Lets start with inherent. Inherent summons are a way to summon specific monsters, that can special summon themselves from either hand, grave, Extra deck(synchro and XYZ) or some even from deck (only one i can think of from deck is Red-eyes Black Metal Dragon). You can identify summons as inherent by reading the text of the card closely if it is made recently, alot of older cards are not so easy to identify.(Synchro and XYZ are always inherent). If the card has a ; in its way of summoning, you can most likely be sure that it is NOT an inherent summon. These summons can be negated by all effects that say they negate monster summons. Example: “Must first be Special Summoned (from your hand) by banishing 1 LIGHT and 1 DARK monster from your Graveyard.”
Now, Non-inherent summons are kinda tricky. What makes them special is that they are not cards that summon themselves, but Effects that activate(often their own effects, but still effects) and just by case, they include summoning a monster, which might / might not be themselves. Cards that negate summons CANNOT negate these kinds of summons, because they are not really summons, but effects. Solemn judgment cant negate Effects, can it? If solemn judgment was to negate a summon it would have to activate in the middle of an resolving effect, wich is impossible. Solemn judgment can however negate reborn, because it is a spell, not because it summons.