The difference between fragment and read is the same for RNA-seq, whole genome sequencing, exome sequencing, etc. But there are some terms like 'FPKM' and 'RPKM' where there is additional meaning in an RNA-seq context.
Also, explained in the video above. A paired-end read is one where sequence has been read (from outside inwards off of a sequencing adaptor) and from both ends of a fragment. Since they are generated from the same physical fragment1, they are said to be paired. A single-end read may be generated from only one end of the same fragment.
1 or more precisely in the case of Illumina from a cluster of identical2 PCR amplicons of a fragment,
2 strictly speaking these amplicons will not all be identical due enzyme introduced errors (hopefully random errors)