Translations:Some basics of MBR v/s GPT and BIOS v/s UEFI/32/en
From Manjaro
Once the conversion is complete, there will be a series of gaps between partitions. Gaps at the start and end of the partition set will be related to the inefficiencies mentioned earlier that permit the conversion to work. Additional gaps before each partition that used to be a logical partition exist because of inefficiencies in the way logical partitions are allocated. These gaps are likely to be quite small (a few kilobytes), so you're unlikely to be able to put useful partitions in those spaces. You could resize your partitions with GNU Parted to remove the gaps, but the risks of such an operation outweigh the very small benefits of recovering a few kilobytes of disk space.