Since using <C-w>j and friends for moving between windows is a bit clunky, many people map the window movement directions to one key combination instead of a keychord, for example something like this:
1vim.keymap.set("", "<C-j>", "<C-w>j")
2vim.keymap.set("", "<C-k>", "<C-w>k")
3vim.keymap.set("", "<C-h>", "<C-w>h")
4vim.keymap.set("", "<C-l>", "<C-w>l")
However, having to choose one of four keymaps depending on your current window and the type of split for what is essentially one action – going to a different window – is still quite cumbersome.
Indeed, there is a far simpler method, which seems to be less known: <C-w><C-w> cycles between all windows, regardless of direction and current window. While <C-w><C-w> will be a bit tedious if you have a large screen with many splits, it's far easier to use than the directional window movements if you only have two or three windows.