Depending on the size of the partitioning, you now can’t store a large file on the drive – one that’s well within the size of the overall disk because there’s a logical partition that’s preventing you from doing so! You might even see that there’s a lot less space there, even in total as there might be some unallocated space too.
Have you ever faced the situation where you plug in your pen drive to your computer and find out that there’s more than one new device found? On closer inspection, you find out that it’s the same pen drive, but there are somehow two partitions on it! If you try to remember how this might have happened you’ll probably recollect using it as a bootable disk sometime recently, maybe to install Kali onto your testing laptop? Or maybe to upgrade a rusty old PC to the latest version of windows? Whatever it may be, you’re now stuck with a flash drive with multiple partitions.