Here are my attempts at definitions:
Sanger: A method of sequencing that depends on chain-terminatiing dideoxynucleotides. This sequencing uses the differential flow of DNA sequences of different lengths through a gel to determine the original DNA sequence, producing a single sequence per reaction container.
NGS: Next-generation sequencing, also referred to as 2GS (second-generation sequencing). This term is used to describe the first wave of sequencing technologies that followed Sanger sequencing technology. The use of NGS has become more confusing with the advent of long-read sequencing, because it's a common assumption that "next-generation" refers to the most recent technology (which is incorrect in this case).
HTS: High-throughput sequencing. This term describes any type of sequencing technology that produces large amounts of data, usually in the form of millions of different sequences produced from the same sequencing run.
SBS: Sequencing by synthesis. This term describes a method of sequencing that depends on the synthesis of [DNA] bases in order for sequencing to be carried out. This definition can extend into long-read sequencing (e.g. PacBio sequencers depend on synthesis during sequencing), but is more typically associated with only the second-generation sequencing technology.