Glad to have you here, @Electrician!
These two checkmarks are associated with your online banking transactions. I'm here to share a few insights about this.
To start, the Bold checkmark is for transactions that have been cleared or posted in your bank. While the Thin checkmark is for transactions with corresponding matching transactions in your bank register.
Feel free to leave a comment below if you have any other questions. I'll be always around to lend you a helping hand.