The terminology can get a little confusing sometimes, so I’m posting here how I personally see it. Feel free to correct me, if I’ve gotten something wrong.
Lolicon - It is short for “lolita complex” which is based on the famous book Lolita. The term was imported into Japan from the West and the meaning changed slightly accordingly.
It is largely used to focus on Japanese cartoons or manga (comics) which focus on young characters (ones who appear under 13). These usually have very cutesy characters. The term is also used to refer to people who consume such content.
Depending on the context, it can also be used to refer to pedophiles, ones attracted to girls, although I believe this is largely because they don’t have a separate word for this (needs confirmation?).
I don’t believe there is a term to refer to content containing characters above 13 but below 18?
Loli - It is short for lolita, it has a different meaning in other contexts, but in this case, it’s someone who appears to be very youthful, under 13.
A 700 year old vampire or a 2000 year old descended deity would also be considered a “loli”, if they fit the physical profile as it is based on appearance rather than actual age.
Shotacon - Shotaro complex. It’s the same thing as Lolicon, but it focuses on little boys instead.
Toddlercon - A rare type of lolicon / shotacon which focuses on toddlers.
Schediaphilia - A sexual paraphilia? It’s an attraction to cartoons. I’ve only seen this used a couple of times, so I don’t know commonplace this term is. It does not mean they’re attracted to real kids, but some likely are as-well.