A is for… ALONSO
More than two years after he was given a send-off from the Abu Dhabi paddock, Fernando Alonso is back where many at the time expected him to eventually return - the Formula 1 grid. Now 39, the Spanish two-time world champion says he feels as strong as ever having widened his racing horizons across a multitude of disciplines since his last grand prix and now returns to F1 exactly 20 years after his debut in the sport.
The nostalgic return of one of the sport's greatest drivers is heightened by the fact he's back with the team where he enjoyed his biggest successes, even if the name above the Enstone factory door is now Alpine rather than the more familiar Renault.
B is for… BUDGET CAP
The Covid-19 pandemic led to Formula 1 putting a 12-month pause on the introduction of the sport's new-look cars but accelerated the need to immediately further reduce spending. A cost cap - a first for the sport - on teams' performance spending was always planned for this year but talks during the first lockdown last spring ended with the original limit of $175m per year slashed to $145m.
Further annual reductions, including the possibility of a driver salary cap, are set to follow in future seasons.
C is for... CHANGING LIVERIES
While the 2021 cars may be similar to last year's, the colours most definitely are not.
Along with completely new liveries with Aston Martin green and Alpine blue, there have been redesigns across the grid - with Ferrari's splash of burgundy and green particularly eye-catching. So, get ready for a bright and beautiful grid!
D is for… DOWNFORCE
F1's fastest-ever cars of 2020 have had a downforce trim at the rear for the new season in order to keep speeds, and therefore lap times, under control. Whether or not the rule change to the floor can be best illustrated by a triangle-shaped block of Comte cheese - see the video above - the impact is that perhaps more significant than first thought as teams' designers grapple to make up for the lost downforce.
E is for… EIGHT
In drivers' championship terms, eight represents an unconquered frontier in Formula 1 but is now within the grasp of Lewis Hamilton this year. Level with Michael Schumacher on seven world titles, Hamilton could take the sport's greatest record outright over the next nine months.
F is for... FERRARI
A disastrous fall from title contenders to sixth in the standings last season represented Ferrari's worst season in four decades. With a new signing in Carlos Sainz, a new engine and new chassis, whether F1's most successful team can start fighting their way back towards the front promises to be one of the many storylines of 2021.
G is for... GEORGE
After starring on his Mercedes debut in Bahrain last year, 2021 is a huge year for George Russell as he looks to stake his claim for a full-time seat with the current world champions. Not only is his Williams contract expiring at the end of the season, but so are both Valtteri Bottas and Lewis Hamilton's.
H is for… HANDICAP SYSTEM
Its effects won't be obvious or immediate, but one significant off-track rule change for 2021 is the first form of a handicap system on success in F1. The aerodynamic development time teams now have is based on a sliding success scale worked out on the previous year's Constructors' Championship. It means that, for 2021, world champions Mercedes have the least wind tunnel and CFD time allocated and Williams, last year's 10th place finishers, the most. The long-term goal is, again, to help close up the field into the sport's new era.
I is for... ICONS RETURNING
We've already mentioned Fernando Alonso's comeback, but a return of a British racing icon is also eagerly anticipated for 2021. The Aston Martin name, after 61 years away from the grid, is back.
J is for… JEDDAH
A brand-new city for the F1 calendar when the Saudi Arabian GP holds its first race in December. Jeddah's inaugural race will be hold on a new street track and its 3.8-mile layout will be the second longest on this year's schedule after Spa-Francorchamps. Oh, and the fastest street circuit in F1 history too.
K is for… KNIGHT
Arise, Sir Lewis! F1's seven-time champion became the fourth driver in the sport's history to be awarded a knighthood but is the first to receive the honour while still racing.
L Is for... LONGEST SEASON
Covid-permitting, Formula 1 is set to embark on the longest season in the sport's 71-year history with 23 races scheduled across five continents from Bahrain at the end of March to Abu Dhabi in mid-December.
M is for… MEGA MIDFIELD
Or, maybe not, as to quote Lando Norris: "We're not a midfield pack anymore - there are a lot of teams involved." With the whole field seemingly condensing from front to back in the final year of the current rules era, the pecking order behind Mercedes and Red Bull is almost guaranteed to change from race to race this year.
N is for... NEW NAMES
Not only are there three rookies on the grid this season but there is one completely new team name on the Formula 1 grid... that of Alpine after Renault's big rebrand.
O is for… ONE-HOUR PRACTICES
Practice running is rather easier to explain this year - all three sessions run to 60 minutes. Practice One and Two sessions come in line with Saturday's Practice Three and, while we've lost 60 minutes of Friday running, the flip side is expected to be that the opening day's action is rather busier than before.
P is for... POWER
With an engine freeze on the way next year, manufactures will be desperate to eek out every bit of power unit performance this year - and it could have a major say on the title battle. Honda, in particular, would love to find enough power to help Red Bull challenge Mercedes.
Q is for... (Sprint) QUALIFYING
They're not officially ratified yet, but the expectation is that three Grand Prix weekends this year - Silverstone, Monza and Interlagos - will be the test bed for short races on a Saturday that decide the grid for the Sunday. Introducing Sprint Qualifying.
R is for... RED BULL
Is this the season Red Bull, F1's last champions before Mercedes, finally launch a title bid? It feels more likely this year than any since 2013.
S is for... SCHUMACHER
Nine years after his father Michael's final grand prix, 22-year-old Mick becomes the third different Schumacher to race at the top level. Symbolically, he is also using his dad's 'MSC' timesheet designation. Long-term expectations will inevitably be high but last year's F2 champion, who has tended to show his best form in the second year of a category, faces a learning season at Haas towards the back of the field alongside fellow rookie Nikita Mazepin.
T is for... TEAM-MATE MATCH-UPS
Be it Ricciardo vs Norris, Verstappen vs Perez or Leclerc vs Sainz, there are seven new team-mate pairings on the grid for 2021 and fascinating match-ups whichever way you look.
U is for... UPSETS
There were a staggering 13 different podium sitters last year - along with a shock win for Pierre Gasly and a shock pole position for Lance Stroll. There should be plenty more surprises this year, with the grid closing up.
V is for... VERSTAPPEN
Still only 23 but incredibly already into his seventh season of F1, is this the season that Max Verstappen finally has the car to challenge for the world title? The watching world holds its breath.
W is for... WILLIAMS
After three consecutive seasons at the bottom of the standings, it is vital that Williams - under new ownership, of course - start to fight their way back towards the midfield in 2021.
X is for... XTRA FEEDS
Sky F1 subscriber? Don't forget you can access extra driver on-boards, live timings, driver tracker and the pit lane feed via the Sky Sports App and your Sky Q/HD box during track sessions in the season.
Y is for... YUKI
Japan have provided some popular and talented drivers to the F1 grid over the years but could Yuki Tsunoda be the one to enjoy the most success? A three-time winner in his sole season of F2, the 20-year-old becomes the first driver born in the 21st century to race at the top level. In what could be a very quick AlphaTauri car, Tsunoda is going to be fast and definitely one to watch.
Z is for... ZANDVOORT
If Max Verstappen is in title contention into September, then expect the Netherlands to be rocking as the revamped Zandvoort on the North Sea coast finally makes its F1 return after a three-decade absence.