Go to Setup Menu->Create->Workflows->Process Builder->New->
Add Object You wanna make this workflow work On
Mark "when a record is created or edited"
Add Criteria -> Select a name for this. -> Select "No criteria Just execute the actions!" Save.
Click on Inmidiate actions->Name It-> Choose "Select the xxx record that started your process".
Name the action keep selected "No criteria—just update the records!" and search for the chekbox2 field and put "Reference" as a Type and search for the checkbox1 on the value. Save.
This should make it.
PD: I prefered using Process builder over classic workflows since it's more visual Friendly.