Samplers – Sampler generates one or more sample results. These sample results have many attributes like elapsed time, data size, etc. It allows JMeter to send specific types of requests to the server, through samplers, thread group decides which type of request it need to make. Some of the useful samplers are HTTP request, FTP request, JDBC request etc.
Thread Groups – JMeter is the beginning part of thread group elements. It is an important element of JMeter, where you can set number of users and time to load all the users given in the thread group.
