Shareware is software which is made available with the right to redistribute copies, but it is stipulated that if one intends to use the software, often after a certain period of time, then a license fee should be paid.
Shareware is not the same thing as FOSS (Free and Open Source Software) for two main reasons given below:
The objective of shareware is to make the software available to try for as many users as possible. This is done in order to increase prospective users will to pay for the software.
The software is distributed in binary form and often includes a built-in timed mechanism, which usually limits functionality after a trial period of usually one to three months.