Buffer

Key Binding	Mode	Description
`SPC b 1`	Normal	switch to buffer with number 1
`SPC b 2`	Normal	switch to buffer with number 2
`SPC b 3`	Normal	switch to buffer with number 3
`SPC b 4`	Normal	switch to buffer with number 4
`SPC b 5`	Normal	switch to buffer with number 5
`SPC b 6`	Normal	switch to buffer with number 6
`SPC b 7`	Normal	switch to buffer with number 7
`SPC b 8`	Normal	switch to buffer with number 8
`SPC b 9`	Normal	switch to buffer with number 9
`SPC b p`	Normal	switch to previous buffer
`SPC b n`	Normal	switch to next buffer
`<Tab>`	Normal	swtich to next buffer, equal to `SPC b n`
`<Shift-Tab>`	Normal	switch to previous buffer, equal to `SPC b p`
`SPC b d`	Normal	delete current buffer
`SPC b k`	Normal	kill current buffer

buffer number

Check the details of a certain key binding, e.g., :verbose nmap <Leader>bp:

:verbose nmap <Leader>bp
n  <Space>bp   * :bprevious<CR>
        Last set from ~/.vim/plugged/vim-better-default/plugin/default.vim

Show all buffers via :files, :buffers or :ls, see :h :buffers.