Jamb and jam are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway.
Autocorrect suggests words that start with the same letters. It suggests what word you may want to save time, but quite often, its suggestions couldn’t be more off base and produces humorous results.
Jamb is a noun. It means the vertical trim or moulding in a door frame, whether it’s made of stone, wood, or other material.
Jam is a verb. It can mean to cause something to malfunction, bruise, or break.
For musicians, to jam means to play their instruments together and see what materializes creatively.
Figuratively, jam can be a person describing themselves being in a tough situation: “in a jam.”
Jam is also a noun. It means fruit that’s been cooked with sugar to thicken up. It’s cooled, mashed, and then put into a jar to be used as a spread on toasted breads, biscuits, or muffins.
The following story uses both words correctly:
Jemma worked in contracting,remodeling houses for quick resale. Business was going really well until she jammed her thumb in a door jamb on site. Suddenly she had to delegate a lot of tasks, and this didn’t come easily to her.