Sanitary Pads are different than diapers.
Although a Sanitary Pad absorbs liquid like a diaper does the Sanitary Pad and diapers are not the same thing.
Sanitary Pads are usually small pads that you put in your panties or underwear to catch period blood or urine from urinary incontinence.
The Sanitary pad is meant for small amounts of urine in case you leak urine.
A diaper is much more absorbent and is meant to be worn around the waist and butt like underwear.
Diapers tape on around the body and are meant to be the underwear that is absorbent while sanitary pads are just meant to go in your underwear.
If you leak a lot of urine then you want an adult tape on diaper and if you leak just a small amount of urine then a sanitary pad or incontinence pad would usually work just fine.
A diaper is like what a baby or non potty trained toddler or child wears to pee in and poop in and they pull up between the legs and tape around the waist.
Adult diapers are that way as well.