What can I purchase using ACH?

As a cryptocurrency enthusiast and investor, I'm often exploring new avenues to utilize my digital assets. Could you elaborate on the capabilities of Automated Clearing House (ACH) transactions in terms of what I can actually purchase? I'm particularly interested in understanding if ACH allows for direct purchases of goods and services, or if it's primarily used for transferring funds between bank accounts. Additionally, are there any limitations or restrictions I should be aware of when utilizing ACH for purchasing purposes? Clarifying these points would greatly assist me in determining the practical applications of ACH in my financial transactions.