PCI compliance stands for Payment Card Industry compliance and relates to the way data from payment cards is stored and transmitted online.
SSL isn’t all you need for PCI compliance but it is an important part of it. PCI compliance also includes security assessments and server scans.
Most WooCommerce sites link to a payment gateway for taking credit card payments and we’d recommend that you do the same. That way, you and your customers have the protection of the payment gateway provider.