Video encoding method, video decoding method, and device using same

A non-transitory computer readable storage medium storing a bitstream generated by steps of:

• partitioning a current picture into one or more tiles and one or more slices, wherein a tile is a rectangular region comprising coding tree units and a slice is a sequence of coding tree units;
• and
• encoding the current picture based on the one or more tiles and the one or more slices, to output the bitstream including video information, wherein the video information includes information on the tile and information on the slice,
• wherein a coding tree unit is split into coding units based on a quad-tree structure, and
• wherein in the current picture, 1) for a plurality of tiles included in one slice, the plurality of tiles does not cross a boundary of the one slice, and 2) for a plurality of slices included in one tile, the plurality of slices does not cross a boundary of the one tile.