If a starting hand chart says do such and such with JTs-76s, I am a little confused with this range.

Is it this (only)?

76s
87s
98s
T9s
JTs

What then are these ranges?

JTs-43s and J9s-53s

Thank you for the clarification.

Just keep subtracting one from each card in the first hand until you reach the second hand. Unless one card is the same in both hands. For example,

J9s-53s: Start with J9s (obviously). Subtract one from the J and subtract one from the 9. So the next hand is T8s. Now subtract one from the T, and subtract one from the 8. So the next hand is 97s. Keep going until you reach 53s. So you have J9s, T8s, 97s, 86s, 75s, 64s, and 53s.

AKs-ATs: Start with AKs. Since the first card (A) is the same for both hands, we just keep using the A and just subtract with the second card. So the next hand is AQs. Again, keep the A and subtract one from the Q. So the next hand is AJs. In all, you have AKs, AQs, AJs, and ATs.

KTs-JTs: Similar to the previous example, but the opposite. We keep the second card (T) the same and decrease the first card. So we have KTs, QTs, and JTs.

AA-TT: This should be obvious, but in the same way we subtract one from each card, which results in all the pairs from AA to TT. So we have AA, KK, QQ, JJ, and TT.

JTs and 54s (and T9s, 98s, 87s, 76s, 65s) are suited connectors. Both holecards are directly connected, forming 2/5 of a straight. These kind of hands flop a lot of straight draws. e.g. JTs can flop an OESD on KQx, Q9x, and 98x, and has a gutshot on AKx, AQx, K9x, Q8x, 97x, 87x.

J9s and 53s (and T8s, 97s, 86s, 75s, 64s) are suited gappers (there is one rank between the two cards). These kind of hands flop fewer straight draws than the directly connected holecards. e.g. To flop an OESD with J9s, the flop has to contain a ten, so J9s can only flop 2 OESDs: T8x and QTx. (JTs could flop 3 different OESDs).

Since connectors flop more (and better) straight draws than gappers do, connectors are played more often. In addition, a suited connector like JTs has a better kicker than the J9s suited gapper, if you happen to make a pair of jacks. In short, JTs is a better hand than J9s.

FWIW, a range that contains all suited connectors from AKs to 54s would often be described as "54s+", meaning "any suited connector, 54 suited or better". 53s+ would mean "any suited gapper 53s or better".

PokerPhilospher and ArtyMcFly, thank you both so very much. I was bracing myself for some snarky comments, but you guys were respectful and helpful.

Much appreciated!