To put a bit of a finish on our discussion of searches and seizures, let me define some of the situations where these terms do or do not apply.
A seizure is a police preclusion of your freedom of movement. But not all such preclusions are actually seizures. For example, a traffic stop is a detention not considered a full 4th Amendment seizure. An investigatory detention is not considered a seizure. Often this detention is accompanied by a search which is not considered a search and is referred to as a "Terry pat-down". This is a touching of the clothing to determine whether there are any potential weapons which could harm the officer.
At the airport you are subjected to a warrant-less search to get on an airplane. You may be subjected to additional pat-downs as well. Under a general greater good philosophy the courts have not found these searches to violate the 4th Amendment.
Returning to the traffic stop, once the reason for the stop is completed any further detention may well become an unreasonable seizure. The Supreme Court has held that being required to wait for a drug dog after a refusal to consent to a search is an unreasonable seizure. While talking about drug dogs, the courts have held that their sniffs are not searches, but if they "alert" then that is probable cause for the police to conduct a search.
The courts have been slow to keep up with technology and have probably not been abreast of current technology since Samuel F. B. Morse hooked up his telegraph wire to send a message from the Supreme Court chamber in the basement of the capital to a receiver in Baltimore, in 1844. But it is catching up and has determined that modern smart phones are more than just call making devices. The courts now require warrants to search such phones and you do not have to provide lock codes or other access information on demand by the officer.
Of course, the home is still the primary focus of 4th Amendment search protections. If the police arrive at your door to do a "knock and talk" you do not have to let them inside. If you let them inside that is considered a consent by the courts and you will have waived several arguments later.
As always these are your rights use them or lose them.