Update or reinstall app ?
Which one is better ? Update or reinstall app for an old iphone 5s ? For sake of storage space...
I'm not sure I fully understand what you are wanting to do, but regarding storage space if you delete and then reinstall an app, any data saved by the app will be deleted. If you update, that data will be not be deleted.
Note that some apps save a lot of data -- but it may be data that you have spent a lot of time entering/accumulating and would not want delete. Other apps have minimal data and with some apps if you delete them and then reinstall them, they will have the same amount of data.