[HenryBemis]

Apart from the Investopedia term, and just because language evolved and (unfortuately) semantics/meanings are redefined, nowadays, algo-trading (retail) is when I run an MT4 software on my laptop, it has a EURUSD chart, I attach a bot (EA) on it, I then sync this MT4 installation/instance with a virtual private server (VPS) somewhere on the planet, then I shut down my laptop, and I go to sleep.

For the large organizations, they got far more complicate systems/servers/software, but these practically do the same thing, just on a massive scale.

[auntienomen]

Just so we're clear: In the financial industry anyways, there's an arguably artificial but fairly hard distinction between making investment decisions and executing trades to implement those decisions. The term "algorithmic trading" has generally referred to trade execution, whereas in what you're describing there's a bot using logic to make investment decisions.

The point of all this is that algorithmic trading in the industry sense of the term is a product that banks and brokers can sell to buy side funds. "You make the decisions, and we'll handle the execution." If a large org is using algorithmic trading, there's a good chance they're paying someone to do it for them.