At least that's what I've read from some very influential people, and yet some people would disagree.
Here's my take, along with my experience.
I prefer to think of them as road blocks rather than writer's block. Sometimes you hit a plot point that you aren't sure what to do with. Sometimes characters ask you questions that you don't have the answers to. And sometimes you write yourself into a corner. Where do we go from here? What's an author to do?
Keep moving. If you don't have the answers, move past it. Leave yourself a note to address it later, when you might have a clearer thought process or you can fill in the missing details. But what if it influences what comes next? I'd still advise the detour.
There are some writing programs to help organize your thoughts, and in the time management classes I've taken over the years, they go with the "spoke" approach. Write everything down and then prioritize it later. I have scenes in my book that are playing in my head but which I haven't reached yet. I have a road block in my current work in process (see last week's post). Overall, I've been able to stay fairly well on a linear path, but I did have to leave a "figure this out" note to myself after a couple of days spinning my wheels brainstorming and researching and collecting options to choose from. Oh, and don't forget the distraction of daily life that interferes!
I don't use a fancy writing program--I am proficient in my word processing software enough to bookmark spots to address, or highlight with another color so they pop out at me when I go back over things. Breadcrumbs, I call them. Directions for when I return to the highway from the detour.
Writer's block means you can't write. You're at a standstill. I disagree with that opinion. I reach road blocks in my writing, but I have other routes I can travel until that path is cleared. If, for some reason, an alternate route isn't available, that's when I stop, pull out a pad of paper and a pen and write down goals, motivation and conflict. Where are my characters. Where do they need to go. What's in the way. (Sometimes referred to as plotting ...) This process is usually enough to push the barricades aside, and I'm on my way again.