generally used in formal language, you'd see a sentence that mentioned two things or people; the next sentence would use the words "former and latter." former refers to the first of the two things/people previously mentioned; latter refers to the second of those two things/people.
example (something i wrote elsewhere, discussing today, November 13th, 2009):
paraskevidekatriaphobia (pahr ahss keh vee dehkuh tree uh foh bee uh). Cool! i only knew triskaidekaphobia (triss kuh deh kuh fohbee uh). the former is fear of Friday the 13th; the latter is fear of the number 13.
The values 5.60 meters and 5.6 meters are the same length, with the former expressing the length to two decimal places and the latter to one decimal place. The extra zero in 5.60 helps to indicate the measurement's precision.
Binomial nomenclature and phylogeny both have to do with organisms. The former refers to the modern scientist's system for naming organisms. The latter is about how an organism evolved over time.
Hydrogen and Helium, with the former decreasing and the latter increasing. Rigel is fusing H into He at a prodigious rate and in a million years or so will start to collapse as its fuel runs out.
asexual reproduction is an exact copy made from only one organism. The latter is from two organisms.
Biomaterials can be classified into two main groups: synthetic and natural biomaterials. The latter exhibit several advantages over the former, such as biocompatibility, inherent biodegradability,
The former has 4 sides while the latter has 6 sides.
The former is to be looked at, the latter to be listened to.
Former one is British Spelling & the latter one is American spelling.
The difference between will and are going to do is that the former refers to the future or a later day while the latter means implies on the present.
The opposite of latter is former.
The former is 10 times brighter than the latter.
Former is the first subject in the sentence, latter is the last (usually of two). "A car and a plane are both going to Houston, the latter arrives first." The latter is the plane, the former is the car.
The former is an old process whilst the latter is a new one.
Former and latter are words used to express a time or preference in a sentence. For example, "I can go to the store at noon or midnight, but I prefer the former." In this sentence the word 'former' is associated with 'noon' and the word 'latter' is associated with the word 'midnight.'
A antonym for "former" is "current" or "latter."
take a backseat to the former.
The difference between torte and gateaux is the former is a French cake while the latter is an Australian cake.