work 2 double crochet stitches into the same space

crochet stitch is basically just working 2dc, stitches into the same stitch, but leaving the last loop of every stitch on the hook, when you have worked all 2 stitches you should have 2 loops left on our hook, yarn over and pull the hook thru both loops and tighten it all together with a slip stitch

work 4 double crochet into the same space or stitch

5 double crochet stitches into the same stitch or space

crochet stitch is basically just working 5dc, stitches into the same stitch, but leaving the last loop of every stitch on the hook, when you have worked all 5 stitches you should have 5 loops left on our hook, yarn over and pull the hook thru all five loops and tighten it all together with a slip stitch

is normally applied in the small space between two stitches rather than crocheting through crochet loops, completed stitch is normally a little shorter than a normal crochet stitch, and the overall spaces between stitches become more open. 

bl : back loop only

blo : work in back loop only

Insert hook from front to back around stitch post and work dc stitch around post

Work 1Bpdc, ch1, 1BPdc into the same stitch

chain : most crochet projects start off with a chain, either a chain into a magic ring for rounds or a base or foundation chain for a rowed crochet project, chain can also mean chains within a pattern row, where either a single chain is worked or a number of chains is crocheted, between stitches.

The space left from any amount of chains worked between stitches

A collection of stitches worked and joined together in same stitch

Skip 1 stitch, work required stitches and then cross back over and work stitch into skipped stitch

insert hook from back to front around stitch post and work dc stitch around post

front post double crochet into stitch, chain 1, front post double crochet into same stitch

Work into the next available required stitch as indicated in pattern , this might require skipping stitches in between
 

A crochet stitch that requires yarn to be yarn-over a hook several times to form a puffed stitch
 

Repeat either stitch pattern or stitches at an allocated time as mentioned in the pattern

repeat the instructions following the single asterisk as directed

repeat the instructions as per the mentioned rows in a sequence of the rows listed

The space left from any amount of chains worked between stitches

A collection of individual stitches worked into the same stitch or chain space  and can vary from to  4 to 8 stitches eg. (6dc-shell or 6dc-sh)
 

skip over / dont work into allocated stitches or chain spaces

The space between two crochet stitches

work required stitch in space after crochet stitch, not in stitch.

work required stitch in space before crochet stitch, not in stitch.

1x double crochet, 1x chain 1, 1 x double crochet all into the same stitch