Difference between overflow-wrap and word-break?

Question

What´s the exact difference between overflow-wrap/word-wrap and word-break? And can anybody tell me what´s the better one for breaking

Answer 1

Here are the exact differences: (based on testing in Chrome v81, and confirming my observations by referencing the spec)

white-space

normal (default): collapses whitespace-chains and line-breaks; adds line-breaks where needed
nowrap: collapses whitespace-chains and line-breaks; doesn't add line-breaks
pre-line: collapses whitespace-chains; adds line-breaks where needed
pre-wrap: no collapsing; adds line-breaks where needed
break-spaces: same as pre-wrap, except with spaces able to trigger line-break-adding
pre: no collapsing; doesn't add line-breaks

Note: If the selected white-space value lists "doesn't add line-breaks", the line-break behavior of the following properties is unable to be applied (ie. ignored).

word-break

normal (default): breaks line at end of last word fitting within container [if one exists], else line left unbroken
break-word: breaks line at end of last word fitting within container [if one exists], else at end of container
break-all: breaks line at end of container [can split a word, even with nearby whitespace]

overflow-wrap (legacy name: word-wrap)

normal (default): breaks line at end of last word fitting within container [if one exists], else line left unbroken
break-word: breaks line at end of last word fitting within container [if one exists], else at end of container [if in non-flex container], else line left unbroken
anywhere: breaks line at end of last word fitting within container [if one exists], else at end of container [so same as word-break: break-word]

Note that for overflow-wrap: break-word (as for any combination that leaves lines too long for the container), the unbroken line can cause a flex container to expand beyond the flex ratio specified (forcing other flex containers to shrink to account for the too-long content).