In the top block which lists your abilities, the black/white mark in front of the ability shows your bonus (and proficiency) for Saving throws. It says so under the block.
So when you become the target of a spell that requires a Strength Save to defend against, that's where you look up your bonus to the roll. In your case, it's +5. The black mark in front of Strength shows that you have Proficiency in Strength Saving throws, which means the +5 is made up of your proficiency bonus (probably +2) and your Strength (probably +3).
On the other hand, if you had to make a Wisdom Save, you would not add your proficiency, since there is no black mark in front of it. This means you just add your Wisdom modifier to the roll (the +1).
The lower block shows you what you roll when you make Skill checks. These are not defense rolls, but attempts to accomplish something in the game. Each skill is linked to an Ability. If you have proficiency with the skill, you add your Ability Modifier + Proficiency, if you don't have proficiency you just use your Ability Modifier.
See the difference between Performance and Persuasion; both are skills that are based on Charisma (which gives you +2 to the roll), but because you are proficient in making Persuasion checks, you get a +4 total bonus there since you're adding in your Proficiency.
Note that all the totaled numbers in both blocks have already been calculated. If the DM asks for a roll, just look up the number in the correct column/row and add (or substract) it from your D20. You don't need to add or remove anything from these numbers during play.