Main Difference
The main difference between Motto and Slogan is that the Motto is a short sentence expressing a motivation and Slogan is a motto or phrase used in advertising or other purposes
Motto
A motto (derived from the Latin muttum, ‘mutter’, by way of Italian motto, ‘word’, ‘sentence’) is a maxim; a phrase meant to formally summarize the general motivation or intention of an individual, family, social group or organization. Mottos are usually found predominantly in written form (unlike slogans, which may also be expressed orally), and may stem from long traditions of social foundations, or from significant events, such as a civil war or a revolution. A motto may be in any language, but Latin has been widely used, especially in the Western world.
Slogan
A slogan is a memorable motto or phrase used in a clan, political, commercial, religious, and other context as a repetitive expression of an idea or purpose, with the goal of persuading members of the public or a more defined target group. The Oxford Dictionary of English defines a slogan as “a short and striking or memorable phrase used in advertising.” A slogan usually has the attributes of being memorable, very concise and appealing to the audience.
Motto (noun)
A sentence, phrase, or word, forming part of an heraldic achievement.
Motto (noun)
A guiding principle; a maxim.
Slogan (noun)
A catch phrase associated with the product or service being advertised.
Slogan (noun)
A distinctive phrase of a person or group of people.
Slogan (noun)
A battle cry among the ancient highlanders of Scotland.
Motto (noun)
a short sentence or phrase chosen as encapsulating the beliefs or ideals of an individual, family, or institution
“the family motto is ‘Faithful though Unfortunate’”
Motto (noun)
a phrase which recurs throughout a musical work and has some symbolical significance
“they were developing the use of leitmotifs or mottoes that appear throughout an opera”