"I will have to get used to the Quickbooks terminology."
Yes, when I teach, I point out we are going to learn "QB-ese" so that you can use Help and understand the icons. I had a student whose file had been set up Backwards: Vendors are who you pay for goods and services, and Customers are those you charge. You get an Invoice from the vendor, because you are their Customer; you enter that as a Bill to pay later, if you are accrual basis or otherwise want to accrue something not paid until a later date.
"The terminology I'm used to, in the double entry accounting system, is that there are subsidiary ledger journal entries"
You have a Computer Program doing the work; think Virtual. Example: AR exists by Customer Name, but there is not a literal subledger in the chart of accounts. You can see this if you use Statement Charges, for instance. You take advantage that the Relational Database provides more complexity and the tools provide easy functionality. The Financial and accounting part is simpler, now that we use computers.
"which are periodically summarized"
When you make any transaction, it is Saved to the database right then. Everything is a Live Update, as you work. You will see how the program racks your Net Income, as you see in my attachments.
"and posted to an account in the general ledger, or, in computerized systems, these general ledger balances are summarized immediately, though period end closing entries are still necessary."
Almost no Closing tasks are required on your part. You can use the Help menu to see the Year End task list.
"When you say "splits = details, or allocations", and you speak of "items", maybe this is the way Quickbooks identifies subsidiary ledger accounts / transactions."
No. The Chart of Accounts mostly meets your Entity's tax form filing. The Items List is the operational activities and explains what you make, do, sell, charge, buy, buy and sell. They link to one, two or even three accounts and control the flow. Open Help and search on Work with items. This is how your QB file can been seen as related to a child care, a landlord, a construction, a church, a sporting goods, etc type of operation, even though All of these might file a 1120S tax form.
Items allow you to use quantity, cost and price, for that same "named" thing. You use them on Estimates, Sales Orders, Purchase Orders, Sales Transactions and Purchase transactions. You can Track this is specifically and directly related to a Customer:Job (job = subcustomer) and that is called Job Tracking. You can mark it Billable or not, depending on if you charge this back to them, or are charging them some flat rate, or a progressive invoice of a defined Scope.
And you analyze; you run reports.
"In your example, when you say "charge item" do you mean expense?"
Please see my attachments.
"When you say these can be linked to one income account, it sounds like you mean one general ledger income (or revenue) account. If this is the case, then maybe splits are the way multiple subsidiary accounts (such as individual accounts payable) can be linked"
Can be Avoided. You don't need to micro-manage the chart of accounts.
You don't typically need more than one AP, either. Individual AP" = There is a vendor name on every transaction. Don't create subaccounts, as well. You don't need to work this hard. Don't start out more complex than needed. Use the program and build your level of functionality, your experience, and avoid making Huge Setup errors in the very beginning.
"My organization's Quickbook reports have columns for the general ledger account,"
There are a Bazillion reports. You would need to be more specific using Text, to describe: I use the Reports menu > Company & Financial Reports, and I ran the P&L Standard, and I see XXXX."
Item-based and Job - or name-based reports are more powerful than Financial reports, for this reason: the Relational database gives you access from Any Perspective. Remember, we started this topic with my reply that it is All About Perspective.
"and then Type, Date, Num, Name, Memo, Split, Amount, and Balance. I'm wondering if the "Name" column is another way Quickbooks identifies subsidiary accounts"
Names are Key Fields in the database = unique and Relational.
"or if it's just a way to isolate an aspect of the transaction description (Memo field), like Num is."
No, Names are far more Powerful and functional.
Close your data file. At the No Company Open screen, bottom right = Sample Files. Learn from them.
Please see my attachments.