IFPI GLOBAL ALBUM ALL FORMAT CHART includes ALL forms of consumption of an album: physicals, digital album sales, digital song sales, streams. This is the MAIN albums chart, using the same methodology as the artist and song charts.
"The chart celebrates the best-selling albums of the year across all consumption formats, spanning physical sales, digital downloads, and streaming platforms"
Different formats are weighted according to their value.
IFPI GLOBAL ALBUM SALES CHART is an additional chart, which includes only physical and digital sales of the album. It does not take song sales or streams onto account.
"The chart combines global sales of physical and digital album downloads to rank the top albums of the year."
This is similar to Billboards Billboard 200 chart, which is the main album chart and their Top Album Sales chart, which similarly to IPFI's secondary chart takes into account only physical sales and album downloads.
I am expecting them to start phasing out the IFPI GLOBAL ALBUM SALES CHART in favor of the main chart, which covers all forms of consumption.